picture
RJR-logo

About | BLOGS | Portfolio | Misc | Recommended | What's New | What's Hot

About | BLOGS | Portfolio | Misc | Recommended | What's New | What's Hot

icon

Bibliography Options Menu

icon
QUERY RUN:
11 Jul 2025 at 01:52
HITS:
17392
PAGE OPTIONS:
Hide Abstracts   |   Hide Additional Links
NOTE:
Long bibliographies are displayed in blocks of 100 citations at a time. At the end of each block there is an option to load the next block.

Bibliography on: Microbial Ecology

RJR-3x

Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 11 Jul 2025 at 01:52 Created: 

Microbial Ecology

Wikipedia: Microbial Ecology (or environmental microbiology) is the ecology of microorganisms: their relationship with one another and with their environment. It concerns the three major domains of life — Eukaryota, Archaea, and Bacteria — as well as viruses. Microorganisms, by their omnipresence, impact the entire biosphere. Microbial life plays a primary role in regulating biogeochemical systems in virtually all of our planet's environments, including some of the most extreme, from frozen environments and acidic lakes, to hydrothermal vents at the bottom of deepest oceans, and some of the most familiar, such as the human small intestine. As a consequence of the quantitative magnitude of microbial life (Whitman and coworkers calculated 5.0×1030 cells, eight orders of magnitude greater than the number of stars in the observable universe) microbes, by virtue of their biomass alone, constitute a significant carbon sink. Aside from carbon fixation, microorganisms' key collective metabolic processes (including nitrogen fixation, methane metabolism, and sulfur metabolism) control global biogeochemical cycling. The immensity of microorganisms' production is such that, even in the total absence of eukaryotic life, these processes would likely continue unchanged.

Created with PubMed® Query: ( "microbial ecology" ) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

-->

RevDate: 2025-07-09

Kovarova A, Amadasun M, Hooban B, et al (2025)

Characterisation of Citrobacter freundii and Enterobacter cloacae complex isolates co-carrying blaNDM-1 and mcr-9 from three hospitals.

Journal of global antimicrobial resistance pii:S2213-7165(25)00156-0 [Epub ahead of print].

OBJECTIVES: Antimicrobial resistance (AMR) is a global health concern related to antimicrobial use and the subsequent emergence of resistant organisms, including carbapenemase-producing Enterobacterales (CPE). CPE isolate co-carrying blaNDM-1 and mcr-9.1 have been scarcely reported internationally. The identification of 20 such isolates, including 16 of one species, within a group of three hospitals in one region indicated potential dissemination within and between healthcare facilities.

METHODS: Twenty isolates were pseudo-anonymised and identified via MALDI-ToF MS. Antimicrobial susceptibility testing was performed by disc diffusion and Minimal Inhibition Concentration for colistin was carried out using the UMIC system. Short-read sequencing was conducted using the Illumina MiSeq platform and genomic analysis identified antimicrobial resistance genes, virulence factors and plasmid contigs. Taxonomic classification of draft genomes was bioinformatically assessed using Kraken2.

RESULTS: This collection comprised of Enterobacter hormaechei (n=16) Citrobacter freundii (n=3) and Enterobacter cloacae (n=1) sourced from patient rectal swabs collected during routine screening (n=13) or from healthcare-associated environmental sites (n=7). The E. hormaechei isolates included four different ST types with one unassigned ST. Contig-based plasmid analysis identified 17 plasmid replicon types among the isolates. IncHI2A, IncHI2, and pKPC-CAV1321_1 were detected in all isolates. Linked blaNDM-1 and mcr-9.1 gene spread in hospitals likely occurred via plasmid-mediated transfer rather than spread of E. hormaechei.

CONCLUSIONS: This study represents the first documented instance of blaNDM-1/mcr-9.1 co-occurrence in Europe to date. It highlights the increasing public health threat posed by antimicrobial resistance and underscores the importance of genomic surveillance and clinical screening.

RevDate: 2025-07-10

Sun HJ, Zhao X, Ding J, et al (2025)

Unveiling dynamics of microbial communities, species interactions, and ecological assembly during low-temperature-induced sludge bulking in full-scale wastewater treatment systems.

Bioresource technology, 435:132950 pii:S0960-8524(25)00916-2 [Epub ahead of print].

This study investigated the microbial community characteristics and ecological mechanisms of floating sludge and suspended sludge in a full-scale wastewater treatment plant under low-temperature conditions. Floating sludge exhibited a lower proportion of positive correlations compared to suspended sludge (56.98 % vs. 61.03 %), indicating stronger competition within the microbial community. Null model analysis revealed the roles of deterministic and stochastic processes in shaping the microbial communities, with stochastic processes being dominant. However, deterministic selection played a larger role in floating sludge, highlighting stronger influence of species interactions and temperature fluctuations. Kyoto Encyclopedia of Genes and Genomes (KEGG) metabolic pathway analysis revealed stronger energy metabolism in floating sludge, while suspended sludge microbes were more active in material transport. This study reveals distinct microbial and ecological differences between floating and suspended sludge at low temperatures, providing theoretical support for optimizing wastewater treatment and controlling sludge bulking in cold climates.

RevDate: 2025-07-09
CmpDate: 2025-07-09

Romano F, John U, Laval-Peuto M, et al (2025)

Small Things that Make a Big Difference: Single-Cell Transcriptomic of Nanociliates Reveals Genes Potentially Involved in Mixotrophy.

Microbial ecology, 88(1):72.

Nanociliates play an important role in the microbial food web of oligotrophic marine systems as grazers of picoplankton on one side, and as prey for microplankton, on the other. However, knowledge on their taxonomy, phylogeny, and trophic strategies is very limited, as well as their potential role as mixotrophs. In the present study, we investigated the transcriptomes of five marine planktonic nanociliates isolated from the Eastern Mediterranean Sea. Our aim was the following: (i) to characterize the phylogenetic placement of these cells using concatenated phylotranscriptomic and (ii) to identify genes potentially involved in mixotrophy by focusing on both photosynthesis and digestion-related genes (phagosome, lysosome). Phylogenetic reconstruction revealed that two cells clustered with Tintinnida, while the other three clustered with Oligotrichida. Reciprocal best hits (RHBs) BlastP analysis indicated the presence of genes related to photosynthesis across all the transcriptomes, while the detection of genes associated with phagosome, lysosome, and generic metabolic pathways provided a more informative insight into the mechanism of mixotrophy. These findings suggest that photosynthesis-related genes alone may not be sufficient indicators of mixotrophic potential in nanociliates and highlight the importance of considering additional cellular pathways involved in phagotrophy. Moreover, these transcriptomes will help to establish a basis for the evaluation of differential gene expression in Oligotrichida, Choreotrichida, and Tintinnida, and a step stone for mixotrophic investigation.

RevDate: 2025-07-10

Ceretto A, C Weinig (2025)

A comparison of 16S rRNA-gene and 16S rRNA-transcript derived microbial communities in bulk and rhizosphere soils.

Frontiers in microbiology, 16:1608399.

Root exudates in a plant's rhizosphere alters microbial community membership and activity, which can in turn alter a plant's health and fitness. In this study we characterized bacterial community composition, using 16S rRNA-gene (DNA) sequencing to define total community membership and 16S rRNA-transcripts (RNA) to define protein synthesis potential (PSP) as a proxy of microbial activity in both rhizosphere and bulk soils of a Wyoming native plant Boechera stricta. Using PSP rather than total microbial membership reveals fine-scale differences in genera between the rhizosphere and control soil communities. This study found DNA community analysis alone disproportionately increased the importance of Saccharibacteria and Gemmatimonadetes phyla in the overall soil community profile, and underestimated the importance of several known root associates (Comamonadaceae, Rhizobacter, and Variovorax), which had elevated PSP in the rhizosphere soil. Thus, the use of DNA-vs. RNA-based community characterization reveals that community composition (DNA) may not completely capture community activity (RNA). Analysis of the PSP community profile also indicated elevated levels of proteins associated with carbohydrate and amino acid metabolism in the rhizosphere-associated bacteria, which may shed light on potential mechanisms by which root exudates shape the rhizosphere soil community.

RevDate: 2025-07-08

Kust A, Zorz J, Paniker CC, et al (2025)

Model cyanobacterial consortia reveal a consistent core microbiome independent of inoculation source or cyanobacterial host species.

The ISME journal pii:8193365 [Epub ahead of print].

Cyanobacteria are integral to biogeochemical cycles, influence climate processes, and hold promise for commercial applications. In natural habitats, they form complex consortia with other microorganisms, where interspecies interactions shape their ecological roles. Although in vitro studies of these consortia have significantly advanced our understanding, they often lack the biological replication needed for robust statistical analysis of shared microbiome features and functions. Moreover, the microbiomes of many model cyanobacterial strains, which are central to our understanding of cyanobacterial biology, remain poorly characterized. Here, we expanded on existing in vitro approaches by co-culturing five well-characterized model cyanobacterial strains with microorganisms filtered from three distinct freshwater sources, generating 108 stable consortia. Metagenomic analyses revealed that, despite host and inoculum diversity, these consortia converged on a similar set of non-cyanobacterial taxa, forming a 25-species core microbiome. The large number of stable consortia in this study enabled statistical validation of both previously observed and newly identified core microbiome functionalities in micronutrient biosynthesis, metabolite transport, and anoxygenic photosynthesis. Furthermore, core species showed significant enrichment of plasmids, and functions encoded on plasmids suggested plasmid-mediated roles in symbiotic interactions. Overall, our findings uncover the potential microbiomes recruited by key model cyanobacteria, demonstrate that laboratory-enriched consortia retain many taxonomic and functional traits observed more broadly in phototroph-heterotroph assemblages, and show that model cyanobacteria can serve as robust hosts for uncovering functional roles underlying cyanobacterial community dynamics.

RevDate: 2025-07-08

Kellom M, Berg M, Chen I-MA, et al (2025)

Tetranucleotide frequencies differentiate genomic boundaries and metabolic strategies across environmental microbiomes.

mSystems [Epub ahead of print].

UNLABELLED: Microbiomes are constrained by physicochemical conditions, nutrient regimes, and community interactions across diverse environments, yet genomic signatures of this adaptation remain unclear. Metagenome sequencing is a powerful technique to analyze genomic content in the context of natural environments, establishing concepts of microbial ecological trends. Here, we developed a data discovery tool-a tetranucleotide-informed metagenome stability diagram-that is publicly available in the integrated microbial genomes and microbiomes (IMG/M) platform for metagenome ecosystem analyses. We analyzed the tetranucleotide frequencies from quality-filtered and unassembled sequence data of over 12,000 metagenomes to assess ecosystem-specific microbial community composition and function. We found that tetranucleotide frequencies can differentiate communities across various natural environments and that specific functional and metabolic trends can be observed in this structuring. Our tool places metagenomes sampled from diverse environments into clusters and along gradients of tetranucleotide frequency similarity, suggesting microbiome community compositions specific to gradient conditions. Within the resulting metagenome clusters, we identify protein-coding gene identifiers that are most differentiated between ecosystem classifications. We plan for annual updates to the metagenome stability diagram in IMG/M with new data, allowing for refinement of the ecosystem classifications delineated here. This framework has the potential to inform future studies on microbiome engineering, bioremediation, and the prediction of microbial community responses to environmental change.

IMPORTANCE: Microbes adapt to diverse environments influenced by factors like temperature, acidity, and nutrient availability. We developed a new tool to analyze and visualize the genetic makeup of over 12,000 microbial communities, revealing patterns linked to specific functions and metabolic processes. This tool groups similar microbial communities and identifies characteristic genes within environments. By continually updating this tool, we aim to advance our understanding of microbial ecology, enabling applications like microbial engineering, bioremediation, and predicting responses to environmental change.

RevDate: 2025-07-09

Goodall T, Busi SB, Griffiths RI, et al (2025)

Soil properties in agricultural systems affect microbial genomic traits.

FEMS microbes, 6:xtaf008.

Understanding the relationships between bacteria, their ecological and genomic traits, and their environment is important to elucidate microbial community dynamics and their roles in ecosystem functioning. Here, we examined the relationships between soil properties and bacterial traits within highly managed agricultural soil systems subjected to arable crop rotations or management as permanent grass. We assessed the bacterial communities using metabarcoding and assigned each amplicon trait scores for rRNA copy number, genome size, and guanine-cytosine (GC) content, which are classically associated with potential growth rates and specialization. We also calculated the niche breadth trait of each amplicon as a measure of social ubiquity within the examined samples. Within this soil system, we demonstrated that pH was the primary driver of bacterial traits. The weighted mean trait scores of the samples revealed that bacterial communities associated with soils at lower pH (<7) tended to have larger genomes (potential plasticity), have more rRNA (higher growth rate potential), and are more ubiquitous (have less niche specialization) than the bacterial communities from higher pH soils. Our findings highlight not only the association between pH and bacterial community composition but also the importance of pH in driving community functionality by directly influencing genomic and niche traits.

RevDate: 2025-07-09
CmpDate: 2025-07-07

Karlsson CJ, Gerlee P, J Rowlett (2025)

An adaptive dynamics framework for microbial ecology and evolution.

Scientific reports, 15(1):24307.

Adaptive dynamics describes a deterministic approximation of the evolution of scalar- and function-valued traits. We construct an evolutionary process for a game-theoretic model which may describe the evolution of microbes. In our analysis, we demonstrate the existence of solutions to the adaptive dynamics and determined their regularity. Moreover, we identify all stationary solutions and prove that these are precisely the Nash equilibria of the game theoretic model. Numerical examples are provided to highlight the main characteristics of the dynamics. The dynamics are unstable; non-stationary solutions oscillate and perturbations of the stationary solutions do not shrink. Instead, a linear type of branching may occur. This may explain the ever-increasing complexity in microbial biological systems and provide a mechanistic explanation for not only the tremendous biodiversity observed in microbe species but also for the extensive phenotypic variability within species.

RevDate: 2025-07-09
CmpDate: 2025-07-07

Wang C, Zhang L, Kan C, et al (2025)

Benefits and challenges of host depletion methods in profiling the upper and lower respiratory microbiome.

NPJ biofilms and microbiomes, 11(1):130.

Metagenomic sequencing for respiratory pathogen detection faces two challenges: efficient host DNA depletion and the representativeness of upper respiratory samples for lower tract infections. In this study, we benchmarked seven host depletion methods, including a new method (F_ase), using bronchoalveolar lavage fluid (BALF), oropharyngeal swab (OP), and mock samples. All methods significantly increased microbial reads, species richness, genes richness, and genome coverage while reduced bacterial biomass, introduced contamination, and altered microbial abundance. Some commensals and pathogens, including Prevotella spp. and Mycoplasma pneumoniae, were significantly diminished. F_ase demonstrated the most balanced performance. High-resolution microbiomes profiling revealed distinct microbial niche preferences and microbiome disparities between the upper and lower respiratory tract. In pneumonia patients, 16.7% of high-abundance species (>1%) in BALF were underrepresented (<0.1%) in OP, highlighting OP's limitations as lower respiratory proxies. This study underscores both the potential and challenges of metagenomic sequencing in advancing microbial ecology and clinical research.

RevDate: 2025-07-07

Mars Brisbin M, Acord M, Davitt R, et al (2025)

Exploring the Phaeosphere: Characterizing the microbiomes of Phaeocystis antarctica colonies from the coastal Southern Ocean and laboratory culture.

Journal of phycology [Epub ahead of print].

Interactions between phytoplankton and bacteria play critical roles in shaping marine ecosystems. However, the intricate relationships within these communities-particularly in rapidly changing polar environments-remain poorly understood. We use targeted methods to directly characterize the microbiomes of individual colonies of Phaeocystis antarctica, a keystone phytoplankton species in the Southern Ocean, and showed that colony microbiomes were consistent across individual colonies collected 108 nautical miles apart. These results suggest that hosting specific colony microbiomes is a shared trait across colony-forming Phaeocystis species, with different species hosting colony microbiomes suited to their respective environments. The bacterial orders Alteromonadales, Oceanospirillales, and Sphingomonadales dominated the microbiomes of all field-collected P. antarctica colonies. The relative abundances of bacterial taxa comprising the majority of field-collected colony microbiomes-for example, Paraglaciecola sp. (Alteromonadales) and Nitrincolaceae (Oceanospirillales)-correlated with Phaeocystis abundance in surface waters, highlighting their potential roles in bloom dynamics and carbon cycling. After a year of laboratory culture, we observed a reduction in colony microbiome diversity, and Caulobacterales, Cellvibrionales, and Rhodobacterales dominated the cultured colony microbiomes. Notably, abundant genera in field-collected colony microbiomes that were lost in culture were psychrophiles. The shift in microbiome structure emphasizes the importance of field-based studies to capture the complexity of microbial interactions, especially for species from polar environments that are difficult to replicate in laboratory conditions. This research provides valuable insights into the ecological significance of prokaryotic interactions with a key phytoplankton species and underscores the necessity of considering these dynamics in the context of climate-driven shifts in marine ecosystems.

RevDate: 2025-07-07

Hernandez JB, Hayer SS, Alvarez S, et al (2025)

Microbiome and metabolome association network analysis identifies Clostridium_sensu_stricto_1 as a stronger keystone genus candidate than Bifidobacterium in the gut of common marmosets.

mSystems [Epub ahead of print].

The common marmoset (Callithrix jacchus), a nonhuman primate species, is a model organism of great interest due to its translational value in a variety of research settings, including the field of microbiomics. While the composition of the marmoset's gut microbiome has been somewhat described in captivity, little is known about how gut microbiota interact with each other over time and how they relate to metabolite production. To help answer this, we characterized interactions in the gut microbiome of the common marmoset by calculating the Spearman correlation coefficient between 16S rDNA-derived relative genera abundance data and targeted metabolomics data collected longitudinally from 10 captive marmosets. Association network graphs were used to visualize significant correlations and identify genera and metabolites that have high degree centrality, marking them as more influential within the microbiome. The genus Clostridium_sensu_stricto_1 engaged in the most metabolomic associations, indicating that it potentially plays a gatekeeping role over metabolites involved in microbial growth and signaling. Its associations with downregulated taurine and bile acids further suggest Clostridium_sensu_stricto_1 modifies bile acids to exert its influence. Flavonifractor and several Bacteroidales members had the most bacterial associations and were negatively associated with Bifidobacterium, indicating a potential competitive relationship. To further characterize microbiome interactions, we performed hierarchical clustering on significant within-dataset associations and developed a new "Keystone Candidate Score" metric that identified Clostridium_sensu_stricto_1 and Alloprevotella as the most influential bacteria (so-called candidate keystone genera) in the marmoset gut microbiome.IMPORTANCEPrevious studies have identified significant individuality within the gut microbiome of common marmosets. The reasons for this inter-subject variability and how it relates to health in captivity are poorly understood, owing to a lack of knowledge regarding dynamic interactions between specific microbiota. To that end, this study characterized significant temporal associations between the gut microbiome and metabolome of healthy captive marmosets. Our findings suggest that certain microbial taxa exert a stronger influence within the gut than others. Specifically, Bifidobacterium was the most abundant genus and primary driving force behind subject-specific microbiome differences, while Clostridium_sensu_stricto_1 and bacteria from the order Bacteroidales were the main sources, respectively, for significant bacteria-metabolite and bacteria-bacteria associations. Together, this suggests that Bifidobacterium may compete with the other taxa for resources and a metabolic niche in the marmoset microbiome.

RevDate: 2025-07-07

Engelberts JP, Ye J, Parks DH, et al (2025)

GenomeFISH: genome-based fluorescence in situ hybridisation for strain-level visualisation of microbial communities.

The ISME journal pii:8190037 [Epub ahead of print].

Fluorescence in situ hybridisation (FISH) is a powerful tool for visualising the spatial organisation of microbial communities. However, traditional FISH has several limitations, including limited phylogenetic resolution, difficulty visualising certain lineages, and the design and optimis ation of new probes is time consuming and does not scale to the known diversity of microbial life. Here, we present GenomeFISH, a high-throughput, genome-based FISH approach that can differentiate strains within complex communities. Fluorescent probes are generated from the genomes of single cells, which are obtained from environmental or clinical samples through fluorescence activated single-cell sorting (FACS). GenomeFISH can distinguish between strains with up to 99% average nucleotide identity and was successfully applied to visualise strains in mock communities and human faecal samples. Given the superior sensitivity and specificity of GenomeFISH, we envisage it will become widely used for the visualisation of complex microbial systems.

RevDate: 2025-07-07

Reintjes G, Giljan G, Fuchs BM, et al (2025)

Using phenotyping to visualize and identify selfish bacteria: a methods guide.

Microbiology spectrum [Epub ahead of print].

Polysaccharides are dominant components of plant and algal biomass, whose degradation is typically mediated by heterotrophic bacteria. These bacteria use extracellular enzymes to hydrolyze polysaccharides to oligosaccharides that are then also available to other bacteria. Recently, a new mechanism of polysaccharide processing-"selfish" uptake-has been recognized, initially among gut-derived bacteria. In "selfish" uptake, polysaccharides are bound at the outer membrane, partially hydrolyzed, and transported into the periplasmic space without loss of hydrolysis products, thus limiting the availability of smaller sugars to the surrounding environment. Selfish uptake is widespread in environments ranging from the ocean's cool, oxygen-rich, organic carbon-poor waters to the warm, carbon-rich, anoxic environment of the human gut. In this methods paper, we present a detailed guide to identifying selfish bacteria, including techniques for rapidly visualizing selfish uptake in complex bacterial communities, detecting selfish organisms, and distinguishing their activity from that of other community members.IMPORTANCEUnderstanding the role of heterotrophic bacteria in the degradation of organic matter is critical for comprehending carbon cycling and microbial ecology across different environments. This study highlights the significant prevalence of "selfish uptake" among bacteria-often overlooked by standard microbial activity assessments-and presents the method used to quantify and identify these "selfish" bacteria. Found in diverse habitats such as anoxic gut environments, oxygenated waters, sediments, and soils, their widespread presence underscores the necessity of revisiting current methodologies to include these crucial organisms. By identifying and studying selfish bacteria, we can gain detailed insights into how microbial communities function, how carbon flows through ecosystems, and how these processes impact global biogeochemical cycles.

RevDate: 2025-07-07

Chong J, Zhou Y, Li Z, et al (2025)

Hyodeoxycholic acid modulates gut microbiota and bile acid metabolism to enhance intestinal barrier function in piglets.

Frontiers in veterinary science, 12:1610956.

Oral bile acids, particularly hyodeoxycholic acid (HDCA), serve as critical drivers for gut microbial community maturation in mice. In the first study, Cy5-labeled HDCA combined with fluorescence imaging revealed rapid gastrointestinal transit of HDCA in piglets, contrasting with its delayed absorption observed in mice. In the second study, the effects of the oral HDCA supplementation on microbiota-host metabolic interactions were investigated using four piglet model groups: OPM-HDCA (naturally born, raised germ-free (GF), and orally administered HDCA), OPM-CON (naturally born, raised GF, and orally administered PBS), SPF-HDCA (naturally born, raised GF, and received fecal microbiota transplantation (FMT) and HDCA), and SPF-CON (naturally born, raised GF with FMT but no HDCA). The results demonstrated that HDCA administration at 0.2 mg/mL suppressed body weight gain in piglets, which was alleviated by FMT. HDCA significantly altered gut microbiota composition in SPF piglets, markedly increasing the Lactobacillus abundance (37.97% vs. 5.28% in SPF-CON) while decreasing the proportion of Streptococcus (28.34% vs. 38.65%) and pathogenic family Erysipelotrichaceae (0.35% vs. 17.15%). Concurrently, HDCA enhanced intestinal barrier integrity by upregulating tight junction proteins (ZO-1, Claudin, Occludin) and suppressing pro-inflammatory cytokines (TNF-α, IL-1β). Additionally, HDCA significantly upregulated ileal gene expression of CYP7A1 (cytochrome P450 family 7 subfamily A member 1) and TGR5 (G protein-coupled bile acid receptor 1) in both SPF-HDCA and OPM-HDCA groups compared to their respective controls (p < 0.05). These findings demonstrate that HDCA exerts microbiota-dependent effects on growth performance, intestinal barrier function, and bile acid metabolism in piglets. Although 0.2 mg/mL HDCA treatment suppressed body weight gain, it potentially enhanced intestinal barrier integrity by activating the TGR5 signaling pathway and increasing the abundance of beneficial bacteria such as Lactobacillus. These results also highlight the critical role of early-life gut microbiota in nutritional interventions, providing a basis for developing precision nutritional strategies targeting intestinal microbial ecology in piglets.

RevDate: 2025-07-06
CmpDate: 2025-07-06

Yan F, Z Niu (2025)

Impacts of pollution on coral bacterial and metabolites diversity across Dapeng Cove of South China sea.

Scientific reports, 15(1):24107.

Coastal ecosystems are increasingly threatened by anthropogenic activities, including sewage discharge and tourism-related pollution, which alter microbial diversity and biochemical cycles. This study applied molecular techniques to examine the coral microbial diversity, and metabolite composition of seawater across five sites (A-E) in Dapeng Cove, South China Sea, to assess pollution impacts. Sites A and B, within the yacht tourism area, exhibited high microbial diversity, dominated by Synechococcus and Rhodobacteraceae, with minimal pollution effects. Site C, inside a domestic drainage channel, showed moderate pollution, with elevated nitrite (NO2) and nitrate (NO3) levels, microbial taxa linked to organic matter degradation, and increased hydroxy acids and indoles. Sites D and E, located in main sewage channels, experienced severe pollution, characterized by high salinity, low dissolved oxygen, and dominance of pollution-tolerant bacteria such as Exiguobacterium and Tepidibacter. Metabolite analysis revealed elevated fatty acyls, organonitrogen compounds, and amino acids at these sites, highlighting strong anthropogenic influence. Beta diversity analysis (NMDS and ANOSIM) confirmed distinct microbial community structures, while KEGG pathway analysis indicated shifts in metabolic functions, with enrichment in xenobiotic biodegradation and anaerobic respiration in sewage-impacted areas. These findings underscore the detrimental effects of wastewater discharge on microbial ecology and biochemical functions. Urgent interventions, including improved wastewater management and regular environmental monitoring, are recommended to mitigate pollution effects. Future research integrating multi-omics approaches is necessary to evaluate the long-term ecological consequences of pollution and climate variability on coastal microbial communities.

RevDate: 2025-07-07

Lu X, Gao Y, Liu X, et al (2025)

Unlocking microbial community succession and key influencing factors during bioelectrocatalytically-driven simultaneous removal of ammonia nitrogen and sulfate from wastewater.

Bioresource technology, 435:132934 pii:S0960-8524(25)00900-9 [Epub ahead of print].

Ammonia nitrogen (NH4[+]-N) and sulfate (SO4[2][-]) removal by Anaerobic ammonium oxidation (Anammox) and sulfate-reducing bacteria (SRB) was studied in dual-chamber microbial electrolysis cells (MECs). Appropriate anode potential stimulation promoted biofilm formation and enhanced extracellular polymeric substances fluorescence, facilitating electron transfer. The highest NH4[+]-N removal (81.1 %) was achieved at the anode potential of 0.6 V vs. Ag/AgCl after 50 days, coinciding with the increase in electroactive Candidatus_Brocadia from 1.1 % to 27.4 %. Simultaneously, SO4[2][-] removal reached 77.0 %, supported by cathodic biofilms dominated by SRB (Desulfofustis, Desulfomicrobium, and Desulfatirhabdium). Automated machine learning and principal co-ordinates analysis identified the anode potential as the key factor shaping microbial ecology. The appropriate anode potential (0.4-0.6 V vs. Ag/AgCl) promoted cathodic sulfidogenesis, indirectly enhancing electron flow and supporting Anammox process at the anode. These findings demonstrate that MECs hold great promise for simultaneously enhancing anaerobic ammonia oxidation bacteria and SRB activities, enabling efficient NH4[+]-N and SO4[2][-] removal.

RevDate: 2025-07-04

Brotto AC, Kurt H, K Chandran (2025)

Impacts of intermittent and continuous aeration modes on performance, substrate dynamics, and microbial ecology of mainstream nitrification processes.

Water research, 285:124123 pii:S0043-1354(25)01030-9 [Epub ahead of print].

Intermittent and continuous aeration strategies in combination with solids retention time (SRT) were investigated in terms of their impact on the performance and ecology of mainstream nitrification. Two lab-scale reactors (R1 and R2) were seeded with the same inoculum and subjected to intermittent aeration and continuous low aeration, respectively at statistically similar air-supply rates. For both reactors, SRT was progressively decreased from 8 d during Phase I to 4 and 2.5 d during Phases II and III, respectively. Compared to R2 (93 ± 4.8 %), R1 achieved more stable and higher ammonia oxidation (99 ± 0.13 %) averaged across SRTs. In R1, Nitrosospira were the dominant AOB, while in R2, AOB were a combination of Nitrosospira and Nitrosomonas. Among NOB, Nitrospira were more abundant than Nitrobacter for both R1 and R2 across SRTs. Intermittent aeration in R1 supported higher relative abundance of Comammox Nitrospira than R2. Notably, the enrichment patterns for nitrifying bacteria in the two reactors reflected distinct drivers (beyond microbial kinetics), including inoculum composition, extant oxygen or nitrogen concentrations or both. Overall, intermittent aeration strategies are integral to the design of biological nitrogen removal processes, although other considerations such as operational feasibility and process emissions might ultimately influence operating strategies.

RevDate: 2025-07-04

Mol Z, Waegenaar F, Pluym T, et al (2025)

Effect of biofilm, temperature and type of source water on the formation of haloanisoles in a pilot drinking water distribution system.

Water research, 285:124078 pii:S0043-1354(25)00986-8 [Epub ahead of print].

Taste and odor deviations in tap water affect many consumers and cause a preference for bottled water. However, since tap water is more sustainable than bottled water, these issues should be solved and prevented rapidly. Haloanisoles (HAs) have a very low odor threshold concentration (sub ng.L[-1]) and are of considerable concern since they are mainly formed in drinking water distribution systems (DWDS). Understanding their formation and influencing factors is a crucial aspect of addressing these odor problems. Therefore, this study uses a DWDS pilot to closely mimic the complex situation in real DWDS and investigates the (microbial) formation of six HAs regarding biofilm cell density and composition, temperature, and type of source water. Ten to thirty times higher formation was observed when a stable biofilm (5 months, 10 times more biomass) was present, compared to a young biofilm (2 weeks). With a spiked halophenol (HP) concentration of 0.1 mg.L[-1], the HA concentrations produced by a young biofilm were already within the OTC range. The mature biofilm contained a higher variety of HA-producing microorganisms and more O-methyltransferase genes to convert the precursors (HPs) into HAs. Higher temperatures (24 °C instead of 16 °C) increased the formation of each HA by a factor of 2 to 4, although still low HP-HA conversion ratios were observed (0.2 %). Regardless of the temperature and the type of source water, a clear pattern is observed in the type of HAs formed, with 2,3,4-trichloroanisole being the most abundant. This study finally investigated the effectiveness of flushing to mitigate these odorous compounds in DWDS and concludes that their partitioning between the biofilm and water phase affects the performance of flushing procedures.

RevDate: 2025-07-04

Ferrocino I, Buzzanca D, Pagiati L, et al (2025)

The microbial terroir of the Greek olive varieties.

International journal of food microbiology, 441:111332 pii:S0168-1605(25)00277-6 [Epub ahead of print].

The microbial terroir of Greek olive varieties remains underexplored. In this study, 62 samples of olive fruits, collected across the harvest period 2019-2020, were analyzed by high-throughput sequencing. The samples represented 38 olive varieties collected from geographically well distributed regions of Greece. Analysis of the bacterial composition revealed that the geographical area was a significant factor in discriminating samples. The core microbiota included Erwinia, Pseudomonas, and members of the Enterobacteriaceae family. Furthermore, a notable variation in bacterial taxa abundances associated with the geographic location was observed. The sampling area was a key discriminant factor for the mycobiota, and the core mycobiota comprised Alternaria, Taphrina, Candida, Wickerhamomyces anomalus and Penicillium. Finally, Redundancy Analysis (RDA) revealed a notable association between environmental characteristics and microbial composition. Specifically, tree age was associated with certain bacterial and fungal taxa (Pearson's correlation p-value adj.[FDR] < 0.05).

RevDate: 2025-07-04

Saini N, Ghosh A, P Bhadury (2025)

Linking Plastic Degradation Potential and Resistance Gene Abundance in Bacterioplankton Community of the Sundarbans Estuarine Ecosystem.

FEMS microbiology letters pii:8186146 [Epub ahead of print].

Harnessing microbial capabilities offers a promising and sustainable approach to address the global challenge of plastic waste. However, the potential of mangrove microbiomes to degrade diverse plastic polymers remains largely unexplored. In this metagenomic-based study, surface water microbiomes were analysed from the Indian Sundarbans, part of the world's largest contiguous mangrove ecosystem, revealing 748.21 hits per billion nucleotides associated with plastic-degrading enzymes (PDEs) targeting 17 different polymer types. Of these, 72.9% corresponded to synthetic polymers and 27.1% to natural polymers. The highest number of hits (223) was associated with polyethylene glycol-degrading enzymes, representing 26.7% of the total PDEs hits. Taxonomic analysis revealed Deltaproteobacteria and Gammaproteobacteria as key degraders of diverse synthetic plastic polymers, with Deltaproteobacteria emerging as a previously unreported group. This suggests that surface sediments may serve as reservoirs for novel plastic-degrading microbes. Co-occurrence network analysis indicated possible emerging co-selection or complex associations between PDEs, antibiotic resistance genes (ARGs), and metal resistance genes (MRGs). Notably, zinc resistance genes and aminoglycoside-related ARGs showed more associations with PDEs. While the presence of PDEs offers a promising avenue for bioremediation, their application may be complicated by the concurrent rise of ARGs and MRGs within PDE-harbouring microbes. Thus, it highlights the need for careful assessment when employing microbes for plastic bioremediation.

RevDate: 2025-07-03
CmpDate: 2025-07-03

Ivanova EA, Suleymanov AR, Nikitin DA, et al (2025)

Machine learning-based mapping of Acidobacteriota and Planctomycetota using 16 S rRNA gene metabarcoding data across soils in Russia.

Scientific reports, 15(1):23763.

The soil microbiome plays a crucial role in maintaining healthy ecosystems and supporting sustainable agriculture. Studying its biogeographical structure and distribution is essential for understanding the rates and mechanisms of microbially mediated soil ecosystem services. This study aimed to investigate the spatial distribution patterns of Acidobacteriota and Planctomycetota across soils in Russia, summarizing data from 16S rRNA gene metabarcoding of topsoils. A machine learning approach (Random Forest) was employed to generate digital distribution maps using climatic, topographic, vegetation, geological, and soil variables. Model interpration was performed using variable importance assessment and Shapley values. According to the error metrics, the Acidobacteriota model achieved a root mean squared error (RMSE) of 6.67% and an R[2] of 0.41, while the Planctomycetota model achieved an RMSE of 2.04% and an R[2] of 0.46. Both phyla exhibited similar spatial distribution patterns, with relative abundance decreasing from North to South. For Acidobacteriota, vegetation cover, surface temperature, and soil pH were significant predictors, whereas the relative abundance of Planctomycetota was mainly influenced by climatic variables. Specifically, Acidobacteriota were more abundant in areas with dense vegetation, stable surface temperatures, and acidic soils. In contrast, Planctomycetota showed reduced abundance in regions with higher levels of precipitable water vapor. These results highlight the potential of machine learning techniques to visualize predictive biogeographic patterns in soil microbial taxa abundance at the phylum level. Despite limitations related to the heterogeneous nature of source data, focusing on higher taxonomic ranks less sensitive to methodological variation enabled to identify preliminary large-scale distribution trends of microbial phyla in soils.

RevDate: 2025-07-03

Tao Y, Liu D, Shi Q, et al (2025)

Lead exposure in relation to gut homeostasis, microbiota, and metabolites.

Applied and environmental microbiology [Epub ahead of print].

Lead (Pb) is a hazardous heavy metal with no known safe threshold for exposure or consumption, posing significant risks to human health. Pb exposure can cause multiple system damage, depending on exposure levels, duration, and its high bioavailability and bioaccumulative potential. Gastrointestinal tract serves as a primary site for Pb absorption, making it particularly vulnerable to Pb-induced damage, including disruption of gut microbiota composition and metabolic function. This study briefly summarizes the detrimental effects of Pb gut homeostasis, microbial ecology, and host metabolism, which, in turn, further contribute to systemic toxicity. Notably, Pb exposure compromises intestinal barrier integrity, increasing gut permeability and facilitating the translocation of harmful biomolecules into systemic circulation, thereby exacerbating organ dysfunction. Importantly, we underscore that dietary and nutritional interventions such as fiber, probiotic, and vitamin C supplementation is a practicable and effective strategy for mitigating or preventing Pb toxicity.

RevDate: 2025-07-03

Al-Khlifeh E, Khadem S, Hausmann B, et al (2025)

Corrigendum: Microclimate shapes the phylosymbiosis of rodent gut microbiota in Jordan's Great Rift Valley.

Frontiers in microbiology, 16:1639190.

[This corrects the article DOI: 10.3389/fmicb.2023.1258775.].

RevDate: 2025-07-03
CmpDate: 2025-07-03

Herman C, Barker BM, Bartelli TF, et al (2025)

A review of engraftment assessments following fecal microbiota transplant.

Gut microbes, 17(1):2525478.

Fecal Microbiota Transplant (FMT) is a treatment for recurrent Clostridium difficile infections and is being explored for other clinical applications, from alleviating digestive and neurological disorders, to restoring microbiomes impacted by cancer treatment. Quantifying the extent of engraftment following an FMT is important in understanding a recipient's response to treatment. Engraftment and clinical response need to be investigated independently to evaluate an FMT's role (or lack thereof) in achieving a clinical response. Standardized bioinformatics methodologies for quantifying engraftment extent would not only improve assessment and understanding of FMT outcomes, but also facilitate comparison of FMT results and protocols across studies. Here we review FMT studies, integrating three concepts from microbial ecology as framework to discuss how these studies approached assessing engraftment extent: 1) Community Coalescence investigates microbiome shifts following FMT engraftment, 2) Indicator Features tracks specific microbiome features as a signal of engraftment, and 3) Resilience examines how resistant post-FMT recipients' microbiomes are to reverting back to baseline. These concepts explore subtly different questions about the microbiome following FMT. Taken together, they provide holistic insight into how an FMT alters a recipient's microbiome composition and provide a clear framework for quantifying and communicating about microbiome engraftment.

RevDate: 2025-07-02

Brinck JE, Sinha AK, Laursen MF, et al (2025)

Intestinal pH: a major driver of human gut microbiota composition and metabolism.

Nature reviews. Gastroenterology & hepatology [Epub ahead of print].

In the human gastrointestinal tract, pH is a key factor in shaping gut microbial composition and activity, while also being influenced by microbial metabolism. pH varies substantially along the gastrointestinal tract within an individual and between different individuals due to a combination of host, diet, microbial and external factors. The importance of pH on microbiota composition and metabolic response has been widely explored over the past century. Here, we review the literature to explore the major physiological and dietary factors that influence pH along the gastrointestinal tract. From a microbial ecology perspective, we discuss how gastrointestinal pH affects microbiota composition and metabolism. We explore mechanisms by which pH can influence bacterial acid response systems, gene expression and the production of microbial metabolites important for health. Finally, we review the literature regarding the potential role of gastrointestinal pH in human diseases. We propose that we can advance our understanding of the gut microbiota in health and disease by considering gastrointestinal pH. We argue that pH-mediated gut microbial metabolic variation is highly important for predicting and manipulating metabolic output relevant to human health.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Puche E, Roger B, Vargas-Sánchez M, et al (2025)

Freshwater macrophyte type (macroalgae versus phanerogams) mainly determines detritus-derived greenhouse gases production: A microcosm experiment.

Journal of environmental sciences (China), 157:674-689.

Freshwater ecosystems are crucial in the global emissions of greenhouse gases (GHGs) such as CH4. Macrophytes are the main organic matter (i.e., detritus) supplier to the sediment of these systems, thus controlling CH4 production. However, species-specific differences (structure and composition) may determine contrasting patterns of detritus transformation into CH4. Furthermore, eutrophication can affect the degradation and, consequently, CH4 production. We performed a 64-day microcosm experiment with anoxic incubations of detritus from seven phylogenetically different macrophytes (two charophytes, filamentous algae -Spirogyra, Cladophora-, three submerged plants and an amphibious one), under two trophic conditions (oligo- versus eutrophic) and with/without sediment. We assessed the CH4 and CO2 production and the changes in the detritus quality at the end of the experiment. The ranking in the mean cumulative CH4 production was: Chara hispida > Nitella hyalina > Najas marina ≈ Teucrium scordium > Stuckenia pectinata ≈ Myriophyllum spicatum > filamentous algae, and it was related to the detritus quality. GHGs maximum production rates were 1.6 (N. marina)-1.2 (C. hispida) mmol CH4/(g OC·day) and 1.7 (N. marina)-1.5 (C. hispida) mmol CO2/(g OC·day). The CO2:CH4 ratio was biased towards CO2 during the first 10 days (average ratio of 200) and fell afterwards to about 1 for all macrophyte species and treatments. The sediment favored detritus decomposition (probably due to the "positive priming effect"), increasing GHGs production. The influence of nutrient enrichment was not evident. Delving into the macrophyte detritus quality-GHGs production relationship is needed to forecast the GHGs emissions in macrophyte-dominated systems.

RevDate: 2025-07-04

Pieńkowska A, Fleischmann J, Drabesch S, et al (2025)

Long-term organic fertilization shields soil prokaryotes from metal stress while mineral fertilization exacerbates it.

Environmental pollution (Barking, Essex : 1987), 382:126747 pii:S0269-7491(25)01120-0 [Epub ahead of print].

Metal contamination in agricultural soils threatens prokaryote dynamics essential for soil health and crop productivity. Yet, whether fertilization in the long-run affects their resilience to metals remains unclear. This study examined the biogeochemical impacts of realistically low-dose applications of cadmium, zinc, and lead in soils subjected to 119 years of non-fertilization, mineral-fertilization (NPK), organic-fertilization (manure), or combined mineral-organic fertilization. Amended metals remained in the mobile fraction with the order: mineral < unfertilized < mineral + organic < organic, mirroring the effects on soil prokaryotes. In both unfertilized and mineral-fertilized soils, 16S rRNA gene copy numbers declined by 30 % upon metal addition, but recovery timing differed: in unfertilized soil, recovery began after three days, whereas in mineral-fertilized soil, numbers declined until day seven before recovering. This coincided with an increase in metal-resistant taxa, particularly in mineral-fertilized soil, with 10 significantly affected OTUs, and to a lesser extent in unfertilized soil, with 5 affected OTUs. Carbon-, nitrogen-, and phosphorus-mining enzyme activities increased 50-100 % in mineral-fertilized soils, suggesting enhanced nutrient acquisition to mitigate metal toxicity. In contrast, organic-fertilized soil hosted stable enzymatic activities and microbial copy numbers with minimal community shifts (1 affected OTU), indicating greater resistance to metal amendment. Combined mineral-organic fertilization stabilized copy numbers and enzymatic activity upon metal amendment, but 8 OTUs were affected, including specialized nutrient cyclers, suggesting increased availability of previously adsorbed NPK cations. Our findings indicate that organic fertilization shields prokaryotes from metal stress, while mineral fertilization exacerbates it, highlighting the benefits of organic practices for maintaining soil health and productivity.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Zhang Z, Yuan G, Turgun X, et al (2025)

Biogeographic Patterns and Ecological Roles of Microorganisms in Sediments Along an Estuarine Salinity Gradient.

Environmental microbiology reports, 17(4):e70139.

The distribution patterns and driving mechanisms of microbial biogeographic patterns are fundamental questions in microbiology. This study analysed and compared the bacterial biogeographic patterns in the coastal environment, focusing on the Yangtze Estuary and its adjacent coastal zone. The purpose is to explore the driving mechanisms under spatial distribution, the community assembly processes and potential functions. Our results revealed that the sediment bacterial community structure exhibited a distinct geographical pattern and was significantly influenced by environmental factors. The microbial community displayed a non-random co-occurrence pattern, and the biogeographic patterns were shaped not only by environmental constraints (deterministic processes) but also by stochastic processes resulting from dispersal limitation. The metagenome sequencing analysis revealed a pronounced salinity gradient in the nitrogen-cycling function of the bacterial community. This functional difference appears to be driven by microbial diversity changes from the estuarine region to the ocean, highlighting the key role of microbial ecological characteristics. The findings of this study contribute to a deeper understanding of microbial ecology in estuarine environments, emphasizing the complex interplay between environmental factors and microbial community dynamics in shaping the function of estuarine sediment bacterial communities.

RevDate: 2025-07-02

Mu D, Chen Q, Gao B, et al (2025)

Oxidized chitosan: Combining an "Adhesion-and-Kill" antibacterial strategy with immunoregulation and angiogenesis to enhance methicillin-resistant Staphylococcus Aureus-infected wound healing.

International journal of biological macromolecules pii:S0141-8130(25)06219-1 [Epub ahead of print].

The emergence of antibiotic-resistant bacteria, particularly methicillin-resistant Staphylococcus aureus (MRSA), presents a significant challenge in clinical wound management due to their resistance to conventional antibiotics and ability to form persistent biofilms. This study explores the antibacterial properties and wound-healing potential of oxidized chitosan (OCTS), fabricated by oxidizing chitosan with hydrogen peroxide (H2O2), which introduces carboxyl groups to enhance its solubility, adhesion, and antibacterial activity. In vitro experiments demonstrate that OCTS exhibits lower MIC concentration (20 mg/mL vs. 80 mg/mL), superior bactericidal efficiency, stronger adhesion to MRSA, and greater biofilm inhibition than conventional chitosan (CTS), while retaining excellent biocompatibility and hemocompatibility. Multi-omics analyses (proteomics and metabolomics) reveal that OCTS disrupts key metabolic, structural, and redox pathways in MRSA. In a MRSA infection model on mouse skin, OCTS effectively eradicated MRSA in wound sites, reduced inflammation, promoted M2 macrophage polarization, and enhanced angiogenesis, culminating in a rapid wound healing rate of 89.2 ± 3.0 % by day 7. Its low cytotoxicity and excellent biosafety in mice further support its clinical translation. These findings highlight OCTS as a promising multifunctional biomaterial for MRSA-infected wound management, integrating antibacterial, immunoregulatory, and regenerative functions through a unique adhesion-and-kill mechanism.

RevDate: 2025-07-02

Liu Z, Wen J, Liu Z, et al (2025)

Tire microplastics rather than polystyrene microplastics reduce soil microbial diversity and network complexity and stability, and induce microbial homogenization.

Journal of hazardous materials, 495:138945 pii:S0304-3894(25)01861-8 [Epub ahead of print].

Microplastics (MPs) pollution poses escalating threats to soil biodiversity, yet its impacts on microbial community structure, stability, and assembly are far from fully understood, limiting the comprehensive assessment of MPs risks. This study investigated effects of polystyrene (PS) and tire particle (TP) MPs (0, 1 %, 5 %; w/w) on soil microbial communities in a maize-planted system, evaluating shifts in diversity, network architecture, and assembly processes. Our results demonstrated that high-concentration (5 %) PS MPs significantly enhanced bacterial α-diversity by promoting some taxa (e.g., Planctomycetes, Betaproteobacteria), and increased bacterial network complexity. In contrast, 5 % TP MPs reduced bacterial and fungal diversity, destabilized bacterial networks, and induced taxonomic homogenization. TP MPs amplified deterministic assembly processes by elevating homogeneous selection contribution while reducing stochastic drift, thereby driving microbial community convergence. Bacterial and fungal community structure shifts under TP MPs correlated with soil stoichiometric alterations, including depleted nitrate nitrogen and available phosphorus, and elevated pH, contents of dissolved organic carbon, ammonium nitrogen, and total carbon. These findings highlight the divergent ecological risks posed by PS and TP MPs, and underscore the urgent need for prioritized mitigation of TP MPs pollution in agroecosystems to preserve microbial functional integrity.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Chao LL, CM Shih (2025)

Molecular Survey and Genetic Identification of Wolbachia Endosymbionts in Dwelling-Caught Culex quinquefasciatus (Diptera: Culicidae) Mosquitoes from Taiwan.

Microbial ecology, 88(1):69.

The genetic identity of Wolbachia endosymbionts was determined in dwelling-caught Culex quinquefasciatus from Taiwan. A total of 370 Cx. quinquefasciatus (245 females and 125 males) was initially screened for Wolbachia infection targeting the universal 16S gene, and the positive samples were further identified their genogroup by a nested-polymerase chain reaction assay to amplify the group-specific Wolbachia surface protein (wsp) gene. In general, 44.59% of Cx. quinquefasciatus was detected with Wolbachia endosymbionts, and 43.2% (54/125) in male and 45.31% (111/245) in female. The group-specific detection was observed in 2.16% (8/370), 41.35% (153/370), and 1.08% (4/370) with groups A, B, and co-infection (A&B), respectively. Phylogenetic analysis revealed that the genetic identities of these Taiwan strains were genetically similar to the groups A and B of Wolbachia with the high sequence homogeneity of 98.7-100% and 96.5-99.8%, respectively. Genetic relatedness is clearly discriminated using both methods of maximum likelihood (ML) and unweighted pair group with arithmetic mean (UPGMA). This study demonstrates the initial genetic identity of Wolbachia endosymbionts with a low prevalence (2.16%) of group A and a high prevalence (41.35%) of group B in dwelling-caught Cx. quinquefasciatus of Taiwan. Because the Cx. quinquefasciatus had been known as a vector for various viral pathogens, the possible impacts of Wolbachia endosymbionts on vector competence of Cx. quinquefasciatus in Taiwan need to be further identified.

RevDate: 2025-07-02
CmpDate: 2025-07-02

He T, Chen Y, Wang Y, et al (2025)

Responses of Microbial Community to Heterogeneous Dissolved Organic Nitrogen Constituents in the Hyporheic Zones of Treated Sewage-Dominated Rivers.

Microbial ecology, 88(1):71.

The hyporheic zone (HZ) of treated sewage-dominated rivers serves as a critical biogeochemical hotspot for dissolved organic nitrogen (DON) transformation, yet the mechanisms linking DON chemodiversity to microbial community dynamics remain poorly resolved. This study integrated spectroscopic fingerprinting, machine learning, and partial least squares path modeling (PLS-PM) to unravel the interactions between redox-stratified DON fractions and microbial consortia in two effluent-impacted rivers (Xi'an, China). The results revealed that DOM spectral parameters associated with distinct DON characteristics posed distinct effects on microbial communities, with the communities in oxic zones largely impacted by autobiogenic, aromatic, and protein-like DON, while the communities in suboxic zones were more intensely impacted by the humification degree of DON. Microbial communities exhibited redox-dependent niche differentiation; i.e., keystone taxa in oxic zones (e.g., Gamma-Proteobacteria) drove nitrogen assimilation, while suboxic taxa (e.g., Verrucomicrobia) prioritized stress-resistant D-amino acid metabolism. PLS-PM demonstrated that biomarkers exerted stronger control on nitrogen cycling (|path coefficients|> 0.6, P < 0.05) than keystone taxa, with summer communities showing higher model fit. Treated sewage-derived DON fostered specialized consortia through biochemical trade-offs, i.e., methionine recycling in oxic zones versus peptidoglycan modification in suboxic zones, thus highlighting the critical role of HZ in mitigating nitrogen pollution. These findings advance predictive modeling of DON-microbe interactions in anthropogenically perturbed aquatic ecosystems.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Nariman N, Entling MH, Krehenwinkel H, et al (2025)

The Microbiome of an Invasive Spider: Reduced Bacterial Richness, but no Indication of Microbial-Mediated Dispersal Behaviour.

Microbial ecology, 88(1):70.

Mermessus trilobatus, an invasive North American linyphiid spider, has expanded its invasion range up to 1400 km in Europe, accelerating its dispersal speed in less than 40 years. The high heritability of dispersal behaviour and the spatial sorting of high and low dispersers indicate a genetic basis of dispersal behaviour. However, microbial endosymbionts can moderate dispersal behaviour in related species (Rickettsia in Erigone atra). Hence, dispersal behaviour in M. trilobatus might also be dictated by the activity of dispersal-mediating endosymbionts. Here, we investigated the microbiome of invasive M. trilobatus spiders extracted from (1) high- and low-dispersive individuals and (2) spiders originating from locations close to the edge and core of the expansion. We examine the microbiomes for the presence of potential dispersal- and reproduction-mediating bacterial strains and compare the microbial assemblages of spiders based on their dispersal behaviour and locations of origin. The composition of microbial assemblages was similar among spiders of different geographic origins and dispersal behaviour. However, microbial richness was lower in high- than in low-dispersive individuals. Surprisingly, none of the known dispersal- or reproduction-altering endosymbionts of arthropods was identified in any tested spider. This contrasts with published results from North America, where M. trilobatus is a known host of Rickettsia and Wolbachia. Thus, the invasive European population appears to have lost its associated endosymbionts. As endosymbionts can reduce spider mobility, it is possible that their absence facilitates the spread of the invasive spider population. The absence of endosymbionts among the analysed individuals substantiates the role of genetic mechanisms behind the variable dispersal behaviour of invasive M. trilobatus in Europe.

RevDate: 2025-07-02

Yao J, Wang H, Fang J, et al (2025)

Distribution Hotspots, Formation Mechanisms, and Ecological Effects of Reactive Oxygen Species in Soil and Sediment: A Critical Review.

Environmental science & technology [Epub ahead of print].

Reactive oxygen species (ROS), including superoxide radical (O2[•-]), hydrogen peroxide (H2O2), hydroxyl radical ([•]OH), and singlet oxygen ([1]O2), are commonly present in soil and sediment, playing a crucial role in the nutrient biogeochemical cycle, pollutant transformation, and microbial ecology. Previous reviews mainly emphasized ROS toxicity and Fenton chemistry-related reactions, neglecting a comprehensive understanding of ROS distribution and hotspots, formation mechanisms, and ecological effects. Here, the most advanced in situ and ex situ detection methods of ROS in soil and sediment are first summarized to address these gaps. ROS hotspots are identified as active microinterfaces and oxic-anoxic fluctuation zones by graphing the distribution of ROS in soil and sediment. Second, ROS formation processes and mechanisms are outlined, which involve natural organic matter (NOM) and biochar (acting as electron shuttle, geobattery, geoconductor, and photosensitizer), transition metals (mainly via Fenton and Fenton-like reactions), and microbes (producing extracellular ROS and mediating NOM decomposition or metal oxides reduction). Further, as for the ecological effects of ROS, they impact the microbial community, nutrient cycle, and the transformation of organic pollutants and multivalence heavy metals. Finally, we call for more future research that focuses on developing rapid and in situ ROS detection techniques, elucidating the interactive ROS formation mechanisms by trace environmental components, analyzing ecological consequences in ROS hotspots, and practically applying ROS in soil and sediment. A comprehensive understanding of the ROS formation process in soil and sediment is crucial for the study of soil carbon sequestration and natural remediation processes in the context of global green and low-carbon development.

RevDate: 2025-07-02

Peters DI, Shin IJ, Deever AN, et al (2025)

Design, development, and validation of new fluorescent strains for studying oral streptococci.

Microbiology spectrum [Epub ahead of print].

Bacterial strains that are genetically engineered to constitutively produce fluorescent proteins have aided our study of bacterial physiology, biofilm formation, and interspecies interactions. Here, we report on the construction and utilization of new strains that produce the blue fluorescent protein mTagBFP2, the green fluorescent protein sfGFP, and the red fluorescent protein mScarlet-I3 in species Streptococcus gordonii, Streptococcus mutans, and Streptococcus sanguinis. Gene fragments, developed to contain the constitutive promoter Pveg, the fluorescent gene of interest, as well as aad9, providing resistance to the antibiotic spectinomycin, were inserted into selected open reading frames on the chromosome that were both transcriptionally silent and whose loss caused no measurable changes in fitness. All strains, except for sfGFP in S. sanguinis, were validated to produce a detectable and specific fluorescent signal. Individual stains, along with extracellular polymeric substances (EPS) within biofilms, were visualized and quantified through either widefield or super-resolution confocal microscopy approaches. Finally, to validate the ability to perform single-cell-level analysis using the strains, we imaged and analyzed a triculture mixed-species biofilm of S. gordonii, S. mutans, and S. sanguinis grown with and without the addition of human saliva. Quantification of the loss in membrane integrity using a SYTOX dye revealed that all strains had increased loss of membrane integrity with water or human saliva added to the growth media, but the proportion of the population stained by the SYTOX dye varied by species. In all, these fluorescent strains will be a valuable resource for the continued study of oral microbial ecology.IMPORTANCEStreptococci are among the earliest colonizers of the soft and hard tissues of the oral cavity and are contributors to the oral health status of the host, with involvement in dental caries, endodontic infections, periodontal disease, and the development of oral cancer. Strains genetically modified to produce fluorescent proteins that can be either visualized through microscopy imaging or quantified by their specific fluorescent intensity signal are critical tools toward the study of individual or mixed-species cultures. Our report here details the development and testing of several new strains of fluorescent oral streptococci that can be utilized in the study of microbial ecology, increasing both the availability of tools and documenting experimental approaches toward in vitro assay applications such as the study of intermicrobial interactions.

RevDate: 2025-07-02

Etesami H (2025)

The dual nature of plant growth-promoting bacteria: Benefits, risks, and pathways to sustainable deployment.

Current research in microbial sciences, 9:100421.

Plant growth-promoting bacteria (PGPB) are pivotal in sustainable agriculture, enhancing crop productivity and reducing reliance on chemical inputs. However, their dual role as beneficial agents and potential stressors remains underexplored. This review examines the paradoxical adverse effects of PGPB, challenging the predominantly optimistic narrative surrounding their use. At the plant level, unintended consequences include hormonal imbalances (e.g., auxin-induced root inhibition), phytotoxic metabolite production (e.g., hydrogen cyanide), and trade-offs between growth and defense mechanisms. At the soil level, risks encompass disrupted microbial diversity, altered nutrient cycling, and horizontal gene transfer that may foster pathogenicity. These outcomes are driven by environmental factors (soil pH and moisture), host-specific interactions, and application practices. Mitigation strategies emphasize rigorous strain selection, optimized dosing, and integrated soil management to balance efficacy with ecological safety. Advances in multi-omics technologies and synthetic consortia design offer predictive insights into strain behavior, while long-term ecological assessments are critical to address legacy impacts. The review underscores the necessity of a nuanced, evidence-based approach to PGPB deployment, harmonizing agricultural benefits with environmental stewardship. By addressing knowledge gaps in microbial ecology and risk assessment, this work supports strategies prioritizing both agricultural resilience and soil biodiversity to ensure PGPB contribute sustainably to global food security.

RevDate: 2025-07-02

Xia Y, Lu L, Wang L, et al (2025)

Multi-omics analyses reveal altered gut microbial thiamine production in obesity.

Frontiers in microbiology, 16:1516393.

OBJECTIVE: Accumulating evidence highlights the important role of B vitamins in maintaining the balance of gut microbial ecology and metabolism, however, few studies have focused on changes in B vitamins homeostasis in the gut and their associations with disease. This study aims to investigate the potential interplay between B vitamins, gut microbiota, and obesity.

METHODS: We conducted an integrated analysis of fecal shotgun metagenomics, fecal metabolome concerning B vitamins and short chain fatty acids (SCFAs), and obese phenotypes in a cohort of 63 participants, including 31 healthy controls and 32 individuals with obesity.

RESULTS: Metabolomic analysis identified significantly lower levels of fecal thiamine in individuals with obesity (P Wilcoxon < 0.001). Fecal thiamine levels exhibited a positive correlation with HDL-C and a negative correlation with BMI, DBP, fasting serum insulin, HOMA-IR, triglycerides, and propionic acid. Binary logistics regression suggested that fecal thiamine deficiency may be a potential contributor to the onset of obesity (Odds ratio: 0.295). Metagenomic analysis indicated that the microbial composition in individuals with obesity was characterized by a predominance of potential opportunistic pathogens, a loss of complexity, and a decrease in thiamine-producing bacteria. Integrated analysis indicated that thiamine deficiency was positively associated with the depletion of thiamine auxotrophic bacteria in the obese microbiome. Functional analysis revealed that KOs content for enzymes involved in the microbial production of thiamine were significantly lower in obesity, including tRNA uracil 4-sulfurtransferase (ThiI, P Wilcoxon = 0.001) and nucleoside-triphosphatase (NTPCR, P Wilcoxon = 0.006), both of which were positively associated with fecal thiamine.

CONCLUSION: Our study highlights the impairment of microbial thiamine production and its broad associations with gut microbiota dysbiosis and obesity-related phenotypes. Our findings provide a rationale for developing treatments that utilize thiamine to prevent obesity by modulating gut microbiota.

RevDate: 2025-07-02

Liu J, Yao P, Liu J, et al (2025)

Habitat and lifestyle affect the spatial dynamics of prokaryotic communities along a river-estuary-sea continuum.

mLife, 4(3):305-318.

Microbial biogeography and its controlling mechanisms are central themes in microbial ecology. However, we still lack a comprehensive understanding of how habitats and lifestyles affect microbial biogeography across complex environmental gradients. In this study, we investigated the planktonic (including free-living [FL] and particle-associated [PA] lifestyles) and benthic prokaryotic communities along a river-estuary-sea continuum of the Changjiang River to explore their distinct spatial dynamics. We observed greater community variability across spatial distances than between habitat and lifestyle types. Spatial variations were evident in FL, PA, and benthic communities, with the highest turnover rates observed in benthic communities, followed by PA, and the lowest turnover rates observed in FL. The replacement effect dominated PA and benthic community variations, whereas the richness effect was more significant in FL communities. Microbial assembly was primarily governed by homogeneous selection and dispersal limitation regardless of habitats/lifestyles, with their ratios decreasing as the spatial distance increased, particularly in the FL fraction. Dispersal limitation had a stronger effect on benthic communities compared to planktonic communities. While heterogeneous selection generally played a minor role, its influence became more pronounced over larger spatial distances and with increasing salinity differences. Finally, we showed that abiotic and biotic factors individually exerted a greater influence on PA communities, whereas their interactions had a stronger effect on FL communities. Our results revealed complex spatial dynamics and assembly mechanisms among microorganisms across different habitats and lifestyles, providing insights into the spatial scaling of community assembly across complex environmental gradients.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Bulzu PA, Henriques Vieira H, R Ghai (2025)

Lineage-specific expansions of polinton-like viruses in photosynthetic cryptophytes.

Microbiome, 13(1):154.

BACKGROUND: Polinton-like viruses (PLVs) are diverse eukaryotic DNA viral elements (14-40 kb) that often undergo significant expansion within protist genomes through repeated insertion events. Emerging evidence indicates they function as antiviral defense systems in protists, reducing the progeny yield of their infecting giant viruses (phylum Nucleocytoviricota) and influencing the population dynamics and evolution of both viruses and their hosts. While many PLVs have been identified within the genomes of sequenced protists, most were recovered from metagenomic data. Even with the large number of PLVs identified from metagenomic data, their host-virus linkages remain unknown owing to the scarcity of ecologically relevant protist genomes. Additionally, the extent of PLV diversification within abundant freshwater taxa remains undetermined. In order to tackle these questions, high-quality genomes of abundant and representative taxa that bridge genomic and metagenomic PLVs are necessary. In this regard, cryptophytes, which are among the most widely distributed, abundant organisms in freshwaters and have remained largely out of bounds of genomic and metagenomic approaches, are ideal candidates for investigating the diversification of such viral elements both in cellular and environmental context.

RESULTS: We leveraged long-read sequencing to recover large (200-600 Mb), high-quality, and highly repetitive (> 60%) genomes of representative freshwater and marine photosynthetic cryptophytes. We uncovered over a thousand complete PLVs within these genomes, revealing vast lineage-specific expansions, particularly in the common freshwater cryptophyte Rhodomonas lacustris. By combining deep sequence homology annotation with biological network analyses, we discern well-defined PLV groups defined by characteristic gene-sharing patterns and the use of distinct strategies for replication and integration within host genomes. Finally, the PLVs recovered from these cryptophyte genomes also allow us to assign host-virus linkages in environmental sequencing data.

CONCLUSIONS: Our findings provide a primer for understanding the evolutionary history, gene content, modes of replication and infection strategies of cryptophyte PLVs, with special emphasis on their expansion as endogenous viral elements (EVEs) in freshwater bloom-forming R. lacustris. Video Abstract.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Flores SS, Cordovez V, Arias Giraldo LM, et al (2025)

Unveiling diversity and adaptations of the wild tomato Microbiome in their center of origin in the Ecuadorian Andes.

Scientific reports, 15(1):22448.

Microbiome assembly has been studied for many plant species and is recognized as a key driver of plant growth and plant tolerance to (a)biotic stresses. To date, assembly of the tomato rhizosphere microbiome has been investigated primarily for commercial varieties and field soils subjected to agricultural management practices, whereas the microbiome of wild tomato genotypes in their native habitats remains largely unexplored. This research focused on distinct populations of Solanum pimpinellifolium in three natural habitats in the Ecuadorian Andes to identify the taxonomic and functional diversity of their rhizosphere microbiome. The results showed that, despite genotypic differences among the wild tomato populations, different soil types and soil microbiome compositions, the rhizosphere microbiome showed strikingly compositional similarity across the three habitats. Proteobacteria, in particular taxa classified as Enterobacteriaceae, and specific unclassified fungal taxa were highly represented in the rhizosphere of S. pimpinellifolum. Metagenomic analyses suggested that the prevalence of Enterobacteriaceae on wild tomato roots may be explained by several traits, in particular nutrient competition, motility, iron acquisition, membrane transport, stress response, and plant hormone biosynthesis. These results reveal a conserved microbiome signature associated with wild tomato rhizosphere in their center of origin. Just as the genomes of wild crop ancestors provide a valuable source of beneficial traits for breeding cultivated varieties, exploring their microbiome in native environments could uncover microbial taxa and traits that similarly contribute to crop growth and health.

RevDate: 2025-07-02
CmpDate: 2025-07-02

Leifels M, Cheng D, Cai J, et al (2025)

Biofilm detachment significantly affects biological stability of drinking water during intermittent water supply in a pilot scale water distribution system.

Scientific reports, 15(1):22408.

Intermittent service provision (IWS) in piped drinking water distribution systems is practiced in countries with limited water resources; it leads to stagnant periods during which water drains completely from de-pressurized pipes, increasing the likelihood of biofilm detachment upon reconnection when water is supplied to the consumer and thus affecting water quality. Our study examines the impact of uninterrupted or continuous water supply (CWS) and IWS on microbial communities and biofilm detachment, using data from three 30-day experiments conducted in an above-ground drinking water testbed with 90-m long PVC pipes containing residual monochloramine. Flow cytometry (FCM) revealed a significant increase in total and intact cell concentrations when water was supplied intermittently compared to CWS, and the microbial alpha-diversity was significantly higher in CWS sections by both 16S rRNA gene metabarcoding and phenotypic fingerprinting of flow cytometry data. Nitrate levels in the water were significantly higher during initial intermittent flow due to the activity of nitrifying bacteria in biofilms exposed to stagnant water in pipes. Overall, biofilm detachment significantly affects the biological stability of drinking water delivered through IWS compared to CWS. We developed a novel biofilm detachment potential index derived from FCM data to estimate the minimum amount of water needed to be discarded before microbial cell counts and community composition return to baseline levels.

RevDate: 2025-07-01

Gisriel CJ, Schluchter WM, Gan F, et al (2025)

Remembering Don Bryant (1950-2024).

Photosynthesis research, 163(4):37.

RevDate: 2025-07-02

Ametefe EN, Thorsen L, Danwonno H, et al (2025)

Molecular Characterization of Culturable Yeasts and Nonspore-Forming Bacteria Associated With Fermented Kapok Seeds (Kantong), a Traditional Food Condiment in Ghana.

International journal of food science, 2025:6452183.

Fermented kapok seeds, known as kantong in northern Ghana, serve as a traditional food condiment which provides flavor and improves the protein content of soups. In this study, the occurrence of yeasts, lactic acid bacteria (LAB), and other nonspore-forming bacteria in kantong was investigated. Microbial enumeration and phenotypic characterizations on isolated strains were performed. Molecular methods were also employed for grouping and identification of strains, and these included random amplification of polymorphic DNA (RAPD) using Escherichia coli phage-derived M13 primer (M13-PCR typing), repetitive element PCR typing (rep-PCR), and 16S rRNA gene sequencing. After a 48-h fermentation period, microbial load ranged from 4.77 ± 0.11 to 8.9 ± 0.1 log10 CFU/g. The pH of the fermenting condiment decreased from 6.5 to 4.7 during the fermentation period. A total of 190 LAB, 53 enterobacteria, and 39 yeasts were identified at species levels using both phenotypic and molecular methods. The LAB included Pediococcus acidilactici, Weissella paramesenteroides, Pediococcus pentosaceus, Weissella confusa, and Lactiplantibacillus plantarum; the enterobacteria isolated were Acinetobacter baumannii, Klebsiella pneumoniae, Enterococcus faecium, Escherichia coli, and Enterobacter cloacae; and the yeasts identified were Nakaseomyces glabratus, Cyberlindnera fabianii, Pichia kudriavzevii, and Saccharomyces cerevisiae. This work presents fermented kapok seeds as a reservoir of microorganisms, some of which could possess some technological properties which could be harnessed to enhance the nutritional value of Ghanaian foods as well as improve gut health as probiotics. It also reveals the presence of enterobacteria in this spontaneous fermentation, thus impacting the safety of the product and the need for starter culture development.

RevDate: 2025-07-01

Sharma H, Al Noman A, Ahmad I, et al (2025)

Bridging Mind and Gut: The Molecular Mechanisms of microRNA, Microbiota, and Cytokine Interactions in Depression.

Current gene therapy pii:CGT-EPUB-149066 [Epub ahead of print].

Depression is a complex psychiatric disorder that arises from various underlying biological mechanisms. In this review, the role of microRNAs (miRNAs) in modulating gut microbiotacytokine communication and their potential to unravel the pathophysiology of depression and develop novel therapeutic strategies are discussed. MiRNAs are small non-coding RNA molecules that have emerged as key regulators in the bidirectional signaling of the gut-brain axis by modulating gene expression and fine-tuning an intricate dialogue between the microbiota, immune system, and central nervous system. Results show how gut microbiota can shape miRNA expression in brain regions involved in mood regulation; conversely, evidence is accumulating, elucidating how miRNA perturbations can shape microbial ecology. Gut bacteria-derived short-chain fatty acids (SCFAs) fuel this nexus by exerting effects on neurogenesis, neurotransmitter synthesis, neuroinflammation, affective behavior alterations, and depressive-like phenotypes. Pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1β are also known to be associated with depressive symptoms related to altered expression patterns of specific miRNAs across these disorders. This review exposes the novel potential biomarkers and therapeutic targets/strategies to develop innovative methods in the diagnosis and treatment of depression by exploring bidirectional relations among miRNAs, gut microbiota, and cytokines. The knowledge of these molecular networks and pathways has provided the opportunity for designing new-generation therapeutics such as phytobiotics, probiotics, psychobiotics, diet therapies, and nanomedicine based on miRNAs from a future perspective, which will revolutionize the management of mental disorders.

RevDate: 2025-06-30

Bruno JS, Heidrich V, Restini FCF, et al (2025)

Dental biofilm serves as an ecological reservoir of acidogenic pathobionts in head and neck cancer patients with radiotherapy-related caries.

mSphere [Epub ahead of print].

UNLABELLED: Radiotherapy-related caries (RRC) is an aggressive and debilitating oral toxicity that affects half of the patients who undergo radiotherapy for head and neck cancer. However, the etiology of RRC is not fully established, and there are no clinically validated methods for preventing it. To gain a better understanding of the risk factors and the microbiome's role in causing RRC, we compared clinicopathological characteristics, oncological treatment regimens, oral health condition, and the oral microbiota at three different oral sites of radiotherapy-treated patients with (RRC+) and without radiotherapy-related caries (RRC-). We observed no significant differences between these groups in the clinicopathological characteristics and treatment regimens. However, RRC+ patients were older and had poorer oral health conditions at the start of the radiotherapy treatment, with a lower number of teeth and a higher proportion of rehabilitated teeth. RRC+ patients had lower microbiota diversity and the dental biofilm of RRC+ patients displayed striking alterations in microbiome composition compared to RRC- patients, including enrichment of acidogenic species and altered metabolic potential, with a higher abundance of genes linked to energy-related pathways associated with the synthesis of amino acids and sugars. We also compared the microbiota of RRC+ tissue with conventional caries tissue, revealing lower bacterial diversity and enrichment of Lactobacillaceae members in RRC+. The insights into the irradiated oral microbiota enhance the understanding of RRC etiology and highlight the potential for microbial-targeted therapies in its prevention and treatment.

IMPORTANCE: This study focuses on a dedicated collection of diverse oral sites to comprehensively investigate microbial differences between patients who develop RRC and those who do not. RRC is a severe oral disease that profoundly impacts on the oral health and overall quality of life of cancer survivors. Leveraging shotgun metagenomics, we characterize the unique microbial variations in in vivo irradiated dental biofilms, unveiling novel insights into the microbial ecology of radiotherapy-treated patients. Furthermore, this research integrates extensive data on oral health and oncological profiles, providing a comprehensive understanding of the intricate relationship between oral microbial communities and the outcomes of radiotherapy-induced toxicity.

RevDate: 2025-06-30

Taylor CC, ST Parks (2025)

There and back again: navigating the return to in-person lab work post-pandemic for the Hybrid Microbial Ecology Course-based Undergraduate Research Experience (H-ME-CURE).

Journal of microbiology & biology education [Epub ahead of print].

The Microbial Ecology Course-based Undergraduate Research Experience (ME-CURE) has evolved over time to accommodate student needs and experiences. Prior to the COVID-19 pandemic, the lab was fully in-person, with a shift to in silico, remote learning from 2020 to 2023. In 2024, the ME-CURE was further adapted to return to in-person learning while maintaining some of the remote learning pedagogy. Significantly, the 2024 Hybrid ME-CURE (H-ME-CURE) built upon the findings of prior iterations of the lab such that students in the 2024 cohort entered with lab isolates, primers, and pathways that were ready for testing. This novel version of the ME-CURE synthesized years of in-person and remote, in silico learning to yield a deeper understanding of microbial pathways and improved molecular data including novel gene sequences for further testing. The goal of this work is to provide the tools that were used to help build the H-ME-CURE by combining past in-person and in silico learning methods of the ME-CURE.

RevDate: 2025-06-30

Zhu M, Zhang F, Qiu Z, et al (2025)

White Light Orchestrates Mycoparasitic and Infection Activities by Regulating Expression of Effectors in Trichothecium roseum.

Food science & nutrition, 13(7):e70396.

The fungal developmental processes are orchestrated by white light. Despite the genome assembly of Trichothecium roseum being available, the underlying molecular mechanisms of the white light-mediated developments of T. roseum remain obscure. It was found that white light impaired mycoparasitic activities against the wheat powdery mildew fungus and infection processes on tomato fruits in T. roseum. In vitro and in vivo, white light significantly impaired colony expansion and dramatically increased conidiation of T. roseum. RNA-seq analysis of T. roseum conidia was profiled to illustrate the light-mediated expression of genes. A total of 153 and 666 differentially expressed genes were identified between conidia treated with or without white light at 48- and 96-h post inoculation (hpi). Among genome-wide identified effectors, 8 and 36 effectors were differentially regulated by white light at 48 and 96 hpi, respectively. The core effectors, Tro004101, Tro006854, Tro008316, and Tro004104 were commonly downregulated by white light. Notably, white light regulated gene expression in key metabolic pathways including tryptophan metabolism (3 genes) and tyrosine metabolism (5 genes), as well as the HOG-MAPK signaling cascade. These results demonstrated that white light-compromised T. roseum mycoparasitic and infection activities might be achieved by regulating specific effector expression and differentially modulating metabolism and HOG-MAPK pathways. The genes detected by our transcriptome analysis may be crucial for mycoparasitism and infection by T. roseum and thus serve as targets for future functional analysis. Our findings provide new insights into the white light-orchestrated developments of an important agricultural and economical fungus and will potentially support efforts for the study of fungal effectors.

RevDate: 2025-06-30

Barrero MAO, Varón-López M, LM Peñuela-Sierra (2025)

Competing microorganisms with exclusion effects against multidrug-resistant Salmonella Infantis in chicken litter supplemented with growth-promoting antimicrobials.

Veterinary world, 18(5):1127-1136.

BACKGROUND AND AIM: The widespread use of antibiotic growth promoters (AGPs) in poultry production has been implicated in altering gut microbiota and promoting the excretion of multidrug-resistant (MDR) bacteria into the environment. Salmonella enterica serovar Infantis (Salmonella Infantis [S.I]), a prevalent zoonotic pathogen, has demonstrated increasing resistance in poultry systems. This study aimed to evaluate the efficacy of natural control microorganisms (NCM), Bacillus subtilis and Lactobacillus plantarum, in reducing the abundance of MDR S.I in fresh chicken litter from birds raised with or without AGP supplementation. It also examined how physicochemical properties and microbial dynamics influence pathogen persistence.

MATERIALS AND METHODS: Microcosms were constructed using litter from broilers raised under two dietary regimes (with and without avilamycin). Treatments included combinations of AGP, S.I, and NCM. Bacterial enumeration was performed using selective media, and whole-genome sequencing of S.I was conducted to characterize antimicrobial resistance and virulence genes. Physicochemical parameters (pH, humidity, temperature, and ammonia) were measured and correlated with microbial loads. Antagonistic activity of NCM strains was assessed using agar diffusion assays.

RESULTS: Genome analysis revealed that S.I carried multiple resistance genes (e.g., blaCTX-M-65, tet(A), and sul1) and efflux systems conferring MDR. In vitro assays showed strong antagonism by L. plantarum and moderate activity by B. subtilis. In microcosms, S.I counts significantly decreased in the presence of both AGP and NCM, indicating synergistic inhibition. Conversely, in the absence of AGP, NCM had a limited effect. Statistical analyses showed strong correlations between microbial groups and physicochemical variables, particularly during later production stages.

CONCLUSION: The application of B. subtilis and L. plantarum in chicken litter significantly reduced S.I colonization under AGP supplementation, suggesting their potential as biocontrol agents. These findings support the development of integrated litter management strategies to mitigate zoonotic and resistant pathogen dissemination, particularly in AGP-using systems. However, the effectiveness of such interventions may vary across farms due to differences in microbial ecology and environmental conditions.

RevDate: 2025-06-30
CmpDate: 2025-06-30

Crull S, Hammer E, Mann AE, et al (2025)

Seasonal Host Shifts for Legionella Within an Industrial Water-Cooling System.

Environmental microbiology reports, 17(4):e70132.

Legionella is a genus of environmental bacteria containing pathogenic species such as Legionella pneumophila that are responsible for Legionnaires' disease, a potentially fatal respiratory infection. Disease aetiology can involve Legionella replication intracellularly within protists and this study aimed to characterise the Legionella-protist relationship to develop novel outbreak prevention targets. Water and sediment samples were collected from a water-cooling tower in South Carolina over a 6-month period. Concomitantly, multiple environmental parameters were recorded. Bacterial and eukaryotic communities were characterised using 16S rRNA gene V4 region and a 252 bp fragment of 18S rRNA gene, respectively. Co-occurrence network analyses were performed to elucidate Legionella-protist correlations through time. We found that Legionella correlated with different protists as the seasons progressed. Acanthamoeba correlated with Legionella in early spring followed by Vannella and Korotnevella in late spring and early summer, and were joined by Echinamoeba in mid-summer. Vannella and Acanthamoeba are known potential hosts for Legionella, while Korotnevella is a potential undocumented host. Of the environmental parameters, temperature showed strong correlation with protists genera, suggesting that Legionella abundance was driven by temperature-dependent protist availability. Our results highlight ecological shifts that are associated with elevated Legionella levels, which offers potential targets to help predict and prevent disease outbreaks.

RevDate: 2025-06-29
CmpDate: 2025-06-29

Cornet L, Zaidi SS, Li J, et al (2025)

A BAC-guided haplotype assembly pipeline increases the resolution of the virus resistance locus CMD2 in cassava.

Genome biology, 26(1):185.

BACKGROUND: Cassava is an important crop for food security in the tropics where its production is jeopardized by several viral diseases, including the cassava mosaic disease (CMD) which is endemic in Sub-Saharan Africa and the Indian subcontinent. Resistance to CMD is linked to a single dominant locus, namely CMD2. The cassava genome contains highly repetitive regions making the accurate assembly of a reference genome challenging.

RESULTS: In the present study, we generate BAC libraries of the CMD-susceptible cassava cultivar (cv.) 60444 and the CMD-resistant landrace TME3. We subsequently identify and sequence BACs belonging to the CMD2 region in both cultivars using high-accuracy long-read PacBio circular consensus sequencing (ccs) reads. We then sequence and assemble the complete genomes of cv. 60444 and TME3 using a combination of ONT ultra-long reads and optical mapping. Anchoring the assemblies on cassava genetic maps reveals discrepancies in our, as well as in previously released, CMD2 regions of the cv. 60444 and TME3 genomes. A BAC-guided approach to assess cassava genome assemblies significantly improves the synteny between the assembled CMD2 regions of cv. 60444 and TME3 and the CMD2 genetic maps. We then performed repeat-unmasked gene annotation on CMD2 assemblies and identify 81 stress resistance proteins present in the CMD2 region, among which 31 were previously not reported in publicly available CMD2 sequences.

CONCLUSIONS: The BAC-assessed approach improved CMD2 region accuracy and revealed new sequences linked to virus resistance, advancing our understanding of cassava mosaic disease resistance.

RevDate: 2025-06-29

Richter I, Büttner H, C Hertweck (2025)

Endofungal Bacteria as Hidden Facilitators of Biotic Interactions.

The ISME journal pii:8172461 [Epub ahead of print].

Fungi play pivotal roles in ecology and human health, driving nutrient cycling, supporting antibiotic production, and posing threats through toxin production. Less well-recognized, however, is their ability to harbour endosymbiotic bacteria. Advances in genomics and microscopy have revealed the prevalence of endofungal bacteria across diverse fungal phyla, though their functions are primarily inferred from genomic and transcriptomic studies. Recent functional research has begun to shed light on their influence on fungal pathogenicity, physiology, and ecology. These findings raise fundamental questions about the establishment and benefits of bacterial-fungal endosymbiosis, as well as the role of endosymbionts in mediating fungal interactions with other organisms. This review provides an in-depth analysis of the molecular mechanisms involved in the establishment and persistence of these symbioses. It also summarizes the current understanding of how endofungal bacteria impact fungal interactions with other organisms. For instance, endofungal bacteria contribute to the beneficial effects of fungi on plant health and fitness, protect fungal hosts from fungivorous predators, and enhance fungal virulence against plants, animals, and humans. These discoveries highlight the need for holistic investigations into bacterial-fungal endosymbiosis to fully understand their role in natural ecosystems. A deeper understanding of these multipartite partnerships offers exciting opportunities to improve ecosystem management, food safety, disease control, and crop productivity.

RevDate: 2025-06-28

Zhou B, Niu C, Mao W, et al (2025)

An electrochemical anaerobic dynamic membrane bioreactor for enhanced sludge digestion: Unveiling molecular interactions and microbial mechanisms.

Water research, 285:124080 pii:S0043-1354(25)00988-1 [Epub ahead of print].

This study investigated the effects of stepwise external voltages on an electrochemical anaerobic dynamic membrane bioreactor (EC-AnDMBR) for anaerobic digestion of waste activated sludge. Increasing the applied voltage greatly mitigated membrane fouling, reduced the transmembrane pressure increase rate and enhanced both volatile solids digestion and biogas production. The dynamic membrane structure became looser with fewer biofouling substances, attributed to a 42.6 % increase in the sludge-membrane interaction energy barrier at higher voltages. Electrochemical analysis revealed improved electroactivity of the anaerobic sludge, as evidenced by increased conductivity and reduced internal resistance. The proton-coupled electron transfer (PCET) pathway was promoted, indicated by a significant increase in the hydrogen/deuterium kinetic isotope effect from 616 to 25,990. Molecular simulations of dissolved organic matter (DOM) showed an enrichment of amide and quinone groups, along with stronger hydrogen-bonding and π-cation interactions, which may contribute to the PCET process. Moreover, elevated voltages promoted more deterministic microbial community assembly and reduced upstream microbial immigration. Gene upregulation in organic metabolism, electron/proton transport, and methanogenesis further supported enhanced digestion performance via PCET pathway. These findings offer valuable insights into the molecular mechanisms and microbial ecology of EC-AnDMBR systems, advancing the development of more efficient and sustainable sludge treatment technologies.

RevDate: 2025-06-27

Liu B, Jia M, Nauwynck W, et al (2025)

Hydrogen-powered bacteria enhance organic micropollutant degradation under starvation conditions.

Water research, 285:124052 pii:S0043-1354(25)00960-1 [Epub ahead of print].

Organic micropollutants (OMPs) occur in natural aquatic environments at trace concentrations with suspected adverse effects on the ecosystem and human health. Microbial biodegradation plays a crucial role in OMP-elimination from drinking water resources. However, long-term OMP-biodegradation remains challenging since the metabolic activity of degrading strains is restricted by energy-limited conditions in treatment systems. Molecular hydrogen (H2) has been identified as a universally available energy source utilized by various bacteria under nutrient-starved conditions, and it can be hypothesized that H2 might also support OMP-degrading microbes when other energy carriers are scarce. The potential of H2 as a supporting energy source for OMP-degradation was tested by examining its effect on the biodegradation of 2,6-dichlorobenzamide (BAM) by Aminobacter niigataensis MSH1 and on the physiological status of the MSH1 cells during both nongrowth-linked (500 μg BAM/L) and growth-linked (10,000 μg BAM/L) regimes. MSH1 cells used as inoculum were either not or pre-exposed to H2 and were harvested at different growth phases. During the nongrowth-linked BAM biodegradation, MSH1 pre-exposed to H2 exhibited a 1.2 to 1.5-fold higher initial specific BAM biodegradation rate, resulting in more rapid BAM removal, likely due to the retention of more metabolically active cells, as suggested by a cell vitality assay. During the growth-linked biodegradation, MSH1 pre-exposed to H2 demonstrated accelerated growth with a 1.5-fold higher maximum specific growth rate, which coincided with an improved BAM removal. The positive effects of H2 were only evident for MSH1 cells harvested either at the stationary and/or starvation phase. Evidence of H2 metabolism was supported by H2 consumption measurements. Collectively, this study reveals that microbial H2 metabolism enables OMP-degrading bacteria to sustain metabolic activity under starvation conditions, offering a novel strategy to enhance long-term OMP-biodegradation.

RevDate: 2025-06-27

Quellhorst HE, Ponce MA, Holguin Rocha AF, et al (2025)

The capacity of 3 stored product insect species to vector microbes after increasing dispersal periods.

Journal of economic entomology pii:8169251 [Epub ahead of print].

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae), and Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) are 3 important stored product pests of maize, but there has been little work evaluating how they vector microbes. While there has been some work assessing the microbial ecology of S. zeamais, none has directly assessed whether they transfer microbes to new food patches. Thus, we evaluated the ability of both species to vector microbes when given the opportunity to forage on sterilized potato dextrose agar dishes after a 0, 24, or 72 h dispersal period in a sterilized container. We subsequently photographed the dishes at 3 and 5 d after introduction and quantified the microbial growth using ImageJ. In addition, we isolated unique morphotypes of fungi, extracted DNA and amplified the internal transcribed spacer 5/4 intergenic spacer region, then sequenced to determine fungal identity. We found that 3 species readily vectored several plant pathogenic microbes, including 21 taxa from more than 11 genera, notably Aspergillus spp. Increasing dispersal period (0, 24, 72 h) resulted in a third less microbial growth (mean microbial growth or mean greyscale value from 0 to 255) by S. zeamais after 72 h, while for P. truncatus it resulted in a 2.7-fold increase in microbial growth. Dispersal by S. zeamais (0, 24, 72 h) resulted in 6.6-fold more microbial growth than dispersal by P. truncatus. There was 1.5- to 3.7-fold more microbial growth after 5 d than 3 d by each species. This research has important implications for food safety in the postharvest environment, especially for maize production, storage, and processing.

RevDate: 2025-06-27

Duxbury SJN, Raguideau S, Cremin K, et al (2025)

Niche formation and metabolic interactions contribute to stable diversity in a spatially structured cyanobacterial community.

The ISME journal pii:8168964 [Epub ahead of print].

Understanding how microbial communities maintain stable compositional diversity is a key question in microbial ecology. Studies from pairwise interactions and synthetic communities indicate that metabolic interactions and spatial organisation can influence diversity, but the relevance of these factors in more complex communities is unclear. Here we used a cyanobacterial enrichment community that consistently forms millimetre-scale granular structures, to investigate compositional diversity and its stability. Over a year of passaging in media without significant carbon source, we found stable co-existence of 17 species belonging to diverse bacterial phyla. Metagenomic analysis revealed polysaccharide breakdown genes and complementary vitamin biosynthesis pathways in these species. Supporting these findings, we show growth of several isolated species on cyanobacterial slime components and experimentally verify vitamin exchanges between two members of the community. Several species had genes for (an)oxygenic photosynthesis and sulfur cycling, the expression of which we verified via meta transcriptomics. Consistent with this, we found that the granular structures displayed oxygen gradients with anoxic interiors. Cyanobacteria and other bacteria were distributed on the periphery and insides of these structures, respectively. Perturbation of the community via glucose addition resulted in fold increases of the heterotrophs, whereas disturbing the community by continual shaking led to fold reductions in several heterotrophs, including anoxygenic phototrophs. In contrast, removal of vitamins supplementation did not consistently alter species coverages, due to predicted vitamin sharing amongst community members. Taken together, these findings indicate that spatial organisation, microenvironment niche formation and metabolic interactions contribute to community compositional diversity and stability.

RevDate: 2025-06-29
CmpDate: 2025-06-27

Li B, Jiang L, Johnson T, et al (2025)

Global health risks lurking in livestock resistome.

Science advances, 11(26):eadt8073.

Livestock farming consumes more than 70% of global antibiotics annually, making livestock manures an important vector of anthropogenically influenced antibiotic resistance genes (ARGs). The global pattern of the livestock resistome, its driving mechanisms, and transmission potential to the clinic are not well assessed. We analyzed 4017 livestock manure metagenomes from 26 countries and constructed a comprehensive catalog of livestock ARGs and metagenome-assembled genomes. Livestock resistome is a substantial reservoir of known (2291 subtypes) and latent ARGs (3166 subtypes) and is highly connectable to human resistomes. We depicted the global pattern of livestock resistome and prevalence of clinically critical ARGs, highlighting the role of farm and human antibiotic stewardship in shaping livestock resistome. We developed a risk-assessment framework by integrating mobility potential, clinical significance, and host pathogenic relevance, and prioritized higher risk livestock ARGs, producing a predictive global map of livestock resistome risks that can help guide research and policy.

RevDate: 2025-06-30

Chen J, Pfeifer K, Steensen K, et al (2025)

Bacterial peptide deformylase inhibitors induce prophages in competitors.

bioRxiv : the preprint server for biology.

While antibiotics mediate chemical warfare among microbes, their roles in the wild extend beyond direct growth inhibition(1). Some antibiotics have the potential to mediate interference competition by triggering a bacterial stress response that subsequently activates endogenous viruses integrated in bacterial genomes (prophages). Canonically, this activation is regulated by the SOS response upon DNA damage. Here we show that a metabolite produced by natural isolates of Vibrio ordalii circumvents the SOS response by directly triggering prophage induction in other Vibrio species, co-occurring in the same environment. While the metabolite was previously classified as a broad-spectrum antibiotic, we observe how it acts as a peptide deformylase inhibitor that specifically induces certain prophages, even when target bacterial cells carry multiple other prophages. Its biosynthetic gene cluster, or ord cluster, also encodes its own peptide deformylase (OrdE) which provides self-immunity to producer strains. Likewise, among natural Vibrio isolates that carry similar prophages, resistance against the ord metabolite was found in those that had acquired a divergent second peptide deformylase. Finally, we show that prophage induction by the ord cluster prevents slower-growing producer strains from being outcompeted by their otherwise fast-growing competitors if they carry an inducible prophage. Thus, we demonstrate how natural products play additional impactful roles in communities beyond antibiotic activity and that prophage induction serves as an interference competition strategy, sustaining community diversity.

RevDate: 2025-06-27

Lee EM, Srinivasan S, Purvine SO, et al (2025)

Syntrophic bacterial and host-microbe interactions in bacterial vaginosis.

The ISME journal pii:8176601 [Epub ahead of print].

Bacterial vaginosis (BV) is a common, polymicrobial condition of the vaginal microbiota that is associated with symptoms such as malodor and excessive discharge, along with increased risk of various adverse sequelae. Host-bacteria and bacteria-bacteria interactions are thought to contribute to the condition, but many of these functions have yet to be elucidated. Using untargeted metaproteomics, we identified 1068 host and 1418 bacterial proteins in a set of cervicovaginal lavage samples collected from 20 participants with BV and 9 who were negative for the condition. We identified Dialister micraerophilus as a major producer of malodorous polyamines and identified a syntrophic interaction between this organism and Fannyhessea vaginae that leads to increased production of putrescine, a metabolite characteristic of BV. Although formate synthesis has not previously been noted in BV, we discovered diverse bacteria associated with the condition express pyruvate formate-lyase enzymes in vivo and confirm these organisms secrete formic acid in vitro. Sodium hypophosphite efficiently inhibited this function in multiple taxa. We also found that the fastidious organism Coriobacteriales bacterium DNF00809 can metabolize formic acid secreted by Gardnerella vaginalis, representing another syntrophic interaction. We noted an increased abundance of the host epithelial repair protein transglutaminase 3 in the metaproteomic data, which we confirmed by enzyme-linked immunosorbent assay. Other proteins identified in our samples implicate Finegoldia magna and Parvimonas micra in the production of malodorous trimethylamine. Some bacterial proteins identified represent novel targets for future therapeutics to disrupt BV communities and promote vaginal colonization by commensal lactobacilli.

RevDate: 2025-06-27

Zhang S, Luo Z, Peng J, et al (2025)

Analysis of Cadmium Accumulation Characteristics Affected by Rhizosphere Bacterial Community of Two High-Quality Rice Varieties.

Plants (Basel, Switzerland), 14(12): pii:plants14121790.

Cadmium-contaminated rice poses serious health risks through the bioaccumulation of Cd (cadmium) from soil to edible grains. Cd contamination disrupts soil microbial ecology and alters microbial diversity. However, the role of cultivar-specific rhizosphere microbial communities in modulating Cd uptake remains unclear. In this study, we aimed to elucidate the mechanism underlying variety-dependent rhizosphere microecological remodeling and Cd accumulation in two independently selected late rice varieties, Yuzhenxiang (YZX) and Xiangwanxian 12 (XWX12). Combining physiological and metagenomic analyses, we revealed variety-specific correlations between root Cd accumulation and dynamic changes in soil pH, soil available phosphorus, and rhizosphere bacteria. The key bacterial genera (Variibacter, Nitrospira) showed differential enrichment patterns under Cd stress. In contrast, Galella and Anaeromyxobacter likely reduce Cd bioavailability by modulating phosphorus availability. Overall, this study elucidates that rice cultivars indirectly shape Cd accumulation patterns via rhizosphere microbial remodeling, providing novel insights for microbial remediation strategies in Cd-contaminated farmland.

RevDate: 2025-06-27

Mohammadi T, B Ely (2025)

Dolichocephalovirinae Phages Exist as Episomal Pseudolysogens Across Diverse Soil Bacteria.

Microorganisms, 13(6):.

Interactions between bacteria and bacteriophages are important for the maintenance of soil communities. In this study, we characterized the giant bacteriophages found within diverse soil bacteria and 14 additional phages isolated directly from soil samples. Based on their genome sizes and genetic composition, we concluded that these phages belong to the Dolichocephalovirinae subfamily. In addition, we used pulsed-field gel electrophoresis to show that the genomes of these phages were present as episomal pseudolysogens in the cytoplasm of their host cells. These findings suggest that episomal phages are important components of soil microbial ecosystems. Understanding the interactions between bacteriophages and bacteria is essential for microbial ecology, as they influence nutrient cycling, community composition, and host evolution. Furthermore, these phage-bacteria dynamics offer potential applications in plant disease control, as bacteriophages could serve as biocontrol agents against soilborne pathogens, promoting sustainable agricultural practices.

RevDate: 2025-06-26
CmpDate: 2025-06-26

Dellicour S, Gámbaro F, Jacquot M, et al (2025)

Comparative performance of viral landscape phylogeography approaches.

Proceedings of the National Academy of Sciences of the United States of America, 122(26):e2506743122.

The rapid evolution of RNA viruses implies that their evolutionary and ecological processes occur on the same time scale. Genome sequences of these pathogens therefore can contain information about the processes that govern their transmission and dispersal. Landscape phylogeographic approaches use phylogeographic reconstructions to investigate the impact of environmental factors and variables on the spatial spread of viruses. Here, we extend and improve existing approaches and develop three novel landscape phylogeographic methods that can test the impact of continuous environmental factors on the diffusion velocity of viral lineages. In order to evaluate the different methods, we also implemented two simulation frameworks to test and compare their statistical performance. The results enable us to formulate clear guidelines for the use of three complementary landscape phylogeographic approaches that have sufficient statistical power and low rates of false positives. Our open-source methods are available to the cientific community and can be used to investigate the drivers of viral spread, with potential benefits for understanding virus epidemiology and designing tailored intervention strategies.

RevDate: 2025-06-26

Kobiałka M, Świerczewski D, Walczak M, et al (2025)

Extremely distinct microbial communities in closely related leafhopper subfamilies: Typhlocybinae and Eurymelinae (Cicadellidae, Hemiptera).

mSystems [Epub ahead of print].

UNLABELLED: Among the Hemiptera insects, a widespread way of feeding is sucking sap from host plants. Due to their nutrient-poor diet, these insects enter into obligate symbiosis with their microorganisms involved in the synthesis of components essential for host survival. However, within the Cicadellidae family, there is a relatively large group of mesophyll feeders-Typhlocybinae-that is considered to be devoid of obligate symbiotic companions. In this work, we examine the composition of microorganisms in this subfamily and compare the results with their close relatives-the Eurymelinae subfamily. To study the microbiome, we used high-throughput next-generation sequencing (NGS, Illumina) and advanced microscopic techniques, such as transmission electron microscopy (TEM) and fluorescence in situ hybridization (FISH), in a confocal microscope. In the bodies of Typhlocybinae insects, we did not detect the presence of microorganisms deemed to be obligate symbionts. Their microbial communities consist of facultative symbionts, mainly alphaproteobacteria such as Wolbachia or Rickettsia as well as others that can be considered as facultative, including Spiroplasma, Acidocella, Arsenophonus, Sodalis, Lariskella, Serratia, Cardinium, and Asaia. On the other hand, the Eurymelinae group is characterized by a high diversity of microbial communities, both obligate and facultative, similar to other Cicadomorpha. We find co-symbionts involved in the synthesis of essential amino acids such as Karelsulcia, betaproteobacteria Nasuia, or gammaproteobacteria Sodalis. In other representatives, we observed symbiotic yeast-like fungi from the family Ophiocordycipitaceae or Arsenophonus bacteria inhabiting the interior of Karelsulcia bacteria. Additionally, we investigated some aspects of symbiont transmission and the phylogeny of symbiotic organisms and their hosts.

IMPORTANCE: The Typhlocybinae and Eurymelinae leafhoppers differ significantly in their symbiotic communities. They have different diets, as Typhlocybinae insects feed on parenchyma, which is richer in nutrients, while Eurymelinae, like most representatives of Auchenorrhyncha, consume sap from the phloem fibers of plants. Our work presents comprehensive studies of 42 species belonging to the two above-mentioned, and so far poorly known, Cicadomorpha subfamilies. Phylogenetic studies indicate that the insects from the studied groups have a common ancestor. The diet shift in the Typhlocybinae leafhoppers contributed to major changes in the composition of microorganisms inhabiting the body of these insects. Research on the impact of diet on the microbiome and the subsequent consequences on the evolution and adaptation of organisms plays an important role in the era of climate change.

RevDate: 2025-06-26

Zhao J, Brandt G, Gronniger JL, et al (2025)

Quantifying the contribution of the rare biosphere to natural disturbances.

The ISME journal pii:8174847 [Epub ahead of print].

Understanding how populations respond to disturbances represents a major goal for microbial ecology. While several hypotheses have been advanced to explain microbial community compositional changes in response to disturbance, appropriate data to test these hypotheses is scarce, due to the challenges in delineating rare vs. abundant taxa and generalists vs. specialists, a prerequisite for testing the theories. Here, we operationally define these two key concepts by employing the patterns of coverage of a (target) genome by a metagenome to identify rare populations, and by borrowing the proportional similarity index (PS index) from macroecology to identify generalists. We applied these concepts to time-series (field) metagenomes from the Piver's Island Coastal Observatory (PICO) to establish that coastal microbial communities are resilient to major perturbations such as tropical cyclones and (uncommon) cold or warm temperature events, in part due to the response of rare populations. Therefore, these results provide support for the insurance hypothesis [i.e., the rare biosphere has the buffering capacity to mitigate the effects of disturbance]. Additionally, generalists appear to contribute proportionally more than specialists to community adaptation to perturbations like warming, supporting the disturbance-specialization hypothesis [i.e., disturbance favors generalists]. Several of these findings were also observed in replicated laboratory mesocosms that aimed to simulate disturbances such as a rain-driven washout of microbial cells and a labile organic matter release from a phytoplankton bloom. Taken together, our results advance understanding of the mechanisms governing microbial population dynamics under changing environmental conditions and have implications for ecosystem modeling.

RevDate: 2025-06-27

Mohamadi Nasrabadi A, Eckstein D, Mettke P, et al (2025)

A Virus Aerosol Chamber Study: The Impact of UVA, UVC, and H2O2 on Airborne Viral Transmission.

Environment & health (Washington, D.C.), 3(6):648-658.

The COVID-19 pandemic highlighted the urgent need to control airborne virus transmission, particularly in indoor environments with limited ventilation. This study evaluates the effectiveness of UVA and UVC irradiation, along with hydrogen peroxide (H2O2), in inactivating aerosolized viruses. A 19 m[3] virus aerosol simulation chamber, replicating indoor conditions, was used to simulate human respiratory emissions by aerosolizing Escherichia phage T4 (T4 phages) embedded in a pig mucin medium that mimics respiratory aerosols. Results showed a clear, dose-dependent reduction in viral genome copies with UVC exposure, where a dose of 129.9 mJ/cm[2] reduced over 99% of the viral genome copies. Although less efficient, UVA still contributed to virus inactivation, reducing detectable phages to 20% at 513.30 J/cm[2]. Mucin provided a protective effect, making virus removal more challenging. Hydrogen peroxide enhanced disinfection, with 1.6 ppm reducing viral genome copies by 78%, and higher concentrations (up to 16 ppm) achieving over 99% reduction in the dark condition. The combination of UVA/UVC with H2O2 further enhanced disinfection, eliminating detectable virus genome copies entirely. These findings underscore the potential for using combined UV light and chemical treatments to effectively mitigate airborne viral transmission in enclosed spaces.

RevDate: 2025-06-26
CmpDate: 2025-06-26

Kara K, Yilmaz Öztaş S, E Baytok (2025)

In Vitro Ruminal Metagenomic Profiles and Ruminal Fermentation Variables of Aromatic Plant Pulps.

Veterinary medicine and science, 11(4):e70447.

BACKGROUND: Aromatic plant residues remaining after aromatic oil extraction represent a promising alternative feed source due to their rich bioactive compound content and fibrous structure. However, their fermentative behaviour and microbial degradability in the rumen require evaluation.

OBJECTIVE: This study aimed to determine the nutrient composition, in vitro ruminal gas production, digestibility characteristics and fermentation end-products of aromatic plant pulps (sage, thyme, lavender and yarrow) obtained via hydrodistillation.

METHODS: Dried pulps were analysed for nutrient contents and subjected to in vitro ruminal fermentation for 24 h. Gas production estimated metabolizable energy (ME), net energy for lactation (NEL), organic matter digestibility (OMd), ammonia nitrogen (NH3-N) and short-chain fatty acid (SCFA) profiles were evaluated. Microbial community composition was assessed via 16S rRNA-based metagenomics.

RESULTS: Yarrow pulp had the highest gas production, ME, NEL, OMd and SCFA concentrations (AA, BA, IVA, T-SCFA) (p < 0.05). Thyme pulp exhibited the highest NH3-N levels (75.14 mg/L), suggesting high rumen-degradable protein content. Sage pulp had the lowest NH3-N levels (60.93 mg/L). Microbial composition shifted with fibre content; higher lignin (in lavender) was associated with lower Bacteroidota and higher Firmicutes abundance. Methanogenic archaea (Methanobrevibacter) were least abundant in thyme pulp (p < 0.05).

CONCLUSION: Due to their fermentability and favourable microbial responses, aromatic plant pulps, particularly yarrow, show promise as functional ruminant feed ingredients. These byproducts may enhance ruminal fibre utilization while modulating microbial ecology and reducing methane-associated archaea.

RevDate: 2025-06-26

Luo G, Cheng Y, Xu Y, et al (2025)

Monochromatic Light Impacts the Growth Performance, Intestinal Morphology, Barrier Function, Antioxidant Status, and Microflora of Yangzhou Geese.

Animals : an open access journal from MDPI, 15(12): pii:ani15121815.

This study investigates the effect of monochromatic light on the body weight (BW), melatonin concentration and its receptors expression levels, intestinal health, and gut microorganisms of Yangzhou geese. Green light (GL) significantly increased BW, melatonin and its receptor expression levels, villus height (VH) and villus height/crypt depth (VH/CD) ratio, superoxide dismutase (SOD), catalase (CAT), and total antioxidant capacity (T-AOC) activities, as well as the abundance of Synergistota and Prevotellaceae_UCG-001, compared with white light (WL). Blue light (BL) significantly increased the mRNA expression of melatonin membrane receptor 1a (Mel1a) and nuclear receptor 1α (RORα), VH and VH/CD ratio, CAT activity, cecal microbes diversity, and decreased malondialdehyde (MDA) levels. Red light (RL) significantly decreased average daily feed intake, reduced the abundances of Synergistota and Prevotellaceae_UCG-001, and increased Mel1a and RORα mRNA expression levels, MDA content, and cecum microbial diversity. Moreover, melatonin levels were significantly higher in the GL and BL groups compared to RL. Furthermore, the mRNA expression levels of Claudin-10, Occludin, and occludens-1 (ZO-1) were significantly upregulated under GL or BL exposures compared to the WL group, whereas RL only enhanced the expression levels of ZO-1. Spearman's correlation analysis revealed that the relative abundance of Prevotellaceae_UCG-001 exhibited positive correlations with BW, melatonin and its receptors expression, gut health, and antioxidant capacity. Overall, these findings suggested that GL exposure enhanced melatonin synthesis and its receptors expression, modulated intestinal homeostasis and microbial ecology, and ultimately increased goose BW.

RevDate: 2025-06-25

Costa BF, Sawaya C, Buren JV, et al (2025)

Investigating anaerobic digestion microbiome resilience to high PFOA and PFOS mixtures during cometabolism.

Bioresource technology pii:S0960-8524(25)00843-0 [Epub ahead of print].

Anaerobic digestion (AD) is a reducing environment with high microbial diversity and potential for biotransformation of PFAS. Yet, their fate and impact on the microbial community remains poorly understood. This study evaluated the long-term impact (100 d) of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) spiked at10 mg/L (low) and 100 mg/L (high), respectively. Although resilient to complete system failure, high PFAS concentrations disrupted AD, evidenced by 25-50 % reduction in methane content, 45 %-48 % reduction in cumulative biogas production, and accumulation of butyric acid. No significant decrease in PFAS concentration was observed in the liquid fraction after 100 d relative to the kill controls, indicating PFAS adsorption behavior. However, PFAS concentrations were temporally variable. Microbial community analysis revealed enrichment of notable AD groups, such as Firmicutes, Synergistetes, and Methanomassillicoccus phyla in high PFAS reactors, which underscores the potential for the microbiome adaptation and informs future strategies for PFAS-contaminated sludge treatment.

RevDate: 2025-06-25

Yasin MU, Muhammad S, Chen N, et al (2025)

Nano-engineered biochar enhances soil microbial interactions and maize transcriptomic pathways for cadmium detoxification.

Journal of hazardous materials, 495:139029 pii:S0304-3894(25)01945-4 [Epub ahead of print].

Cadmium (Cd) contamination threatens agroecosystems and food security by degrading soil health, inducing plant oxidative stress, and reducing crop yields. Sustainable strategies integrating biochar (BC) with nanoparticles (NPs) for Cd immobilization and soil-plant-microbe restoration remain underexplored. Here, we demonstrate the efficacy of BC, nano-silicon (nSi), and nano-iron (nFe) to immobilize Cd, improve soil health and reprogram maize stress responses in Cd-contaminated soil. Soil Cd bioavailability, microbial networks, and maize transcriptomes were analyzed under varying BC-nSi-nFe formulations. Among these formulations, the BC + 25 % nSi + 75 % nFe + Cd (T6) composite reduced bioavailable Cd by 21 %, raised soil pH from 6.21 to 6.98, and enhanced soil enzyme activities (118-139 %). T6 improved maize biomass (115-119 %), reduced shoot Cd accumulation (78 %), and suppressed oxidative stress (67-75 % ROS reduction). This study presents transcriptomic evidence showing that BC-NPs composites mitigate Cd stress and modulate maize antioxidant defense and phytohormone signaling pathways, offering new insights into the molecular mechanisms underlying improved plant resilience. Soil microbial networks shifted toward metal-resistant taxa, with enriched glutathione metabolism and nitrogen fixation. BC-NPs composites offer a multidimensional remediation strategy, integrating nanomaterial science, microbial ecology, and plant molecular biology to mitigate Cd toxicity. This approach enhances soil-plant resilience, supporting sustainable agriculture in contaminated ecosystems.

RevDate: 2025-06-25

Ma X, Li Y, Niu L, et al (2025)

Salinity regulates nutrient cycling via top-down and bottom-up forces in artificial cut-off tidal channels: Insights from multitrophic microbiota.

Water research, 285:124037 pii:S0043-1354(25)00945-5 [Epub ahead of print].

Artificial cut-off of natural tidal meanders for flood control has substantially altered microbial communities and their role in nutrient cycling, yet the lack of comprehensive investigations into these specific anthropogenic impacts introduces greater uncertainty regarding the resultant water quality of nutrient-enriched estuaries. Here, we investigated how planktonic multitrophic microbiota and their mediated nutrient cycling respond to artificial meander cut-off using the environmental DNA (eDNA) approach. Results showed that despite the decline in α diversity of multitrophic microbiota, the nutrient cycling potential of the water column was enhanced 2.91-fold in the straight tidal channel. The artificial cut-off restructured the microbial food web, with trophic transfer efficiency from basal species to protozoa increasing. Salinity was identified to be the key environmental driver, mitigating the negative impact of decreased biodiversity on estuarine nutrient cycling potential by intensifying protozoan predation on heterotrophic bacteria (top-down forces). Additionally, salinity further enhanced environmental selection (bottom-up forces), reducing heterotrophic bacterial diversity while promoting the proliferation of functional microbial taxa, such as Comamonadaceae, Chitinophagaceae, and Rhodocyclaceae. This study offers novel insights into nutrient cycling in artificial straight tidal channels and provides critical foundations for optimizing restoration and management strategies in anthropogenically modified tidal river.

RevDate: 2025-06-25
CmpDate: 2025-06-25

de Meireles DA, Souza T, de A A Carneiro K, et al (2025)

Treated Wastewater Irrigation Enhances Plant Biomass, Soil Fertility, and Rhizosphere Microbial Activity in C4 and CAM species Grown on a Degraded Planosol.

Environmental monitoring and assessment, 197(7):804.

The Brazilian semi-arid region, marked by erratic rainfall and severely degraded soils, presents critical challenges for sustainable agriculture. In this context, the reuse of treated domestic wastewater-collected from a septic tank and anaerobic filter system-offers a promising strategy to enhance plant productivity and rehabilitate soil conditions, particularly within the Caatinga biome. This study evaluated the long-term (four-year) effects of irrigation with pure water versus treated domestic wastewater on plant dry biomass, soil fertility, and rhizospheric microbial activity in a degraded Planosol. Two plant types were assessed: a C4 species (Mimosa caesalpiniifolia) and a CAM species (Opuntia atropes). Results demonstrated that treated wastewater irrigation significantly increased dry biomass, with a 12.18% increase in the C4 species and a 29.33% increase in the CAM species. Soil chemical fertility improved notably, with wastewater application raising soil pH by 5.0%, increasing soil organic carbon by 87.9%, and enhancing nutrient availability, including nitrogen, potassium, magnesium, and sodium. A 37.5% reduction in exchangeable aluminum further indicated mitigation of soil acidity. Microbial responses varied between species: while soil respiration increased in both rhizospheres-more prominently in CAM species-microbial biomass carbon rose significantly in the C4 rhizosphere but declined in CAM, suggesting species-specific microbial interactions. These findings support the potential of treated domestic wastewater as a nutrient-rich, low-cost irrigation alternative for improving plant performance and soil quality in semi-arid degraded lands. Nevertheless, potential risks-including salinity build-up and pathogen persistence-necessitate long-term monitoring and further environmental safety assessments. By integrating plant physiology, soil chemistry, and microbial ecology, this study offers a comprehensive approach to evaluating wastewater reuse as a sustainable agricultural and ecological restoration practice in the Caatinga biome.

RevDate: 2017-08-25
CmpDate: 2017-08-25

De Vuyst L, Van Kerrebroeck S, F Leroy (2017)

Microbial Ecology and Process Technology of Sourdough Fermentation.

Advances in applied microbiology, 100:49-160.

From a microbiological perspective, sourdough is to be considered as a specific and stressful ecosystem, harboring yeasts and lactic acid bacteria (LAB), that is used for the production of baked goods. With respect to the metabolic impact of the sourdough microbiota, acidification (LAB), flavor formation (LAB and yeasts), and leavening (yeasts and heterofermentative LAB species) are most noticeable. Three distinct types of sourdough fermentation processes can be discerned based on the inocula applied, namely backslopped ones (type 1), those initiated with starter cultures (type 2), and those initiated with a starter culture followed by backslopping (type 3). A sourdough-characteristic LAB species is Lactobacillus sanfranciscensis. A sourdough-characteristic yeast species is Candida humilis. Although it has been suggested that the microbiota of a specific sourdough may be influenced by its geographical origin, region specificity often seems to be an artefact resulting from interpretation of the research data, as those are dependent on sampling, isolation, and identification procedures. It is however clear that sourdough-adapted microorganisms are able to withstand stress conditions encountered during their growth. Based on the technological setup, type 0 (predoughs), type I (artisan bakery firm sourdoughs), type II (industrial liquid sourdoughs), and type III sourdoughs (industrial dried sourdoughs) can be distinguished. The production of all sourdoughs, independent of their classification, depends on several intrinsic and extrinsic factors. Both the flour (type, quality status, etc.) and the process parameters (fermentation temperature, pH and pH evolution, dough yield, water activity, oxygen tension, backslopping procedure and fermentation duration, etc.) determine the dynamics and outcome of (backslopped) sourdough fermentation processes.

RevDate: 2025-06-25

Popov IV, Peshkova DA, Lukbanova EA, et al (2025)

Gut Microbiota Dynamics in Hibernating and Active Nyctalus noctula: Hibernation-Associated Loss of Diversity and Anaerobe Enrichment.

Veterinary sciences, 12(6): pii:vetsci12060559.

Hibernation in mammals entails profound physiological changes that are known to impact host-associated microbial communities, yet its effects on the gut microbiota of synanthropic bats remain underexplored. In this study, we investigated the gut bacterial composition and diversity of Nyctalus noctula before and during hibernation using high-throughput 16S rRNA amplicon sequencing. Fecal samples from individually banded bats were collected under controlled conditions at a rehabilitation center and analyzed for alpha and beta diversity, as well as differential taxonomic abundance. Hibernation was associated with a marked reduction in microbial diversity according to the Shannon and Simpson indices and a distinct restructuring of gut communities based on the Bray-Curtis dissimilarity index. Active bats exhibited a diverse microbiota enriched in facultative anaerobes, including Lactococcus, Enterococcus, and Escherichia-Shigella, while hibernating individuals were dominated by obligate anaerobes, such as Romboutsia and Paeniclostridium. These findings suggest a contraction and functional specialization of the gut microbiota during torpor, potentially reflecting adaptations to fasting, hypothermia, and reduced gut motility. Our results demonstrate that the bat's gut microbiome is highly responsive to physiological status and underscore the importance of microbial ecology for understanding the host's energy balance and health under seasonal contexts.

RevDate: 2025-06-25
CmpDate: 2025-06-25

Wimmer BC, Dwan C, De Medts J, et al (2025)

Undaria pinnatifida Fucoidan Enhances Gut Microbiome, Butyrate Production, and Exerts Anti-Inflammatory Effects in an In Vitro Short-Term SHIME[®] Coupled to a Caco-2/THP-1 Co-Culture Model.

Marine drugs, 23(6): pii:md23060242.

Fucoidans have demonstrated a wide range of bioactivities including immune modulation and benefits in gut health. To gain a deeper understanding on the effects of fucoidan from Undaria pinnatifida (UPF) on the colonic microbiome, the short-term Simulator of the Human Intestinal Microbial Ecosystem[®], a validated in vitro gut model, was applied. Following a three-week intervention period on adult faecal samples from three healthy donors, microbial community activity of the colonic microbiota was assessed by quantifying short-chain fatty acids while composition was analysed utilising 16S-targeted Illumina sequencing. Metagenomic data were used to describe changes in community structure. To assess the secretion of cytokines, co-culture experiments using Caco-2 and THP1-Blue™ cells were performed. UPF supplementation over a three-week period had a profound butyrogenic effect while also enriching colonic microbial diversity, consistently stimulating saccharolytic genera, and reducing genera linked with potentially negative health effects in both regions of the colon. Mild immune modulatory effects of UPF were also observed. Colonic fermentation of UPF showed anti-inflammatory properties by inducing the secretion of the anti-inflammatory cytokines IL-6 and IL-10 in two out of three donors in the proximal and distal colon. In conclusion, UPF supplementation may provide significant gut health benefits.

RevDate: 2025-06-25

Vieira RIM, Peixoto ADS, Monclaro AV, et al (2025)

Fungal Coculture: Unlocking the Potential for Efficient Bioconversion of Lignocellulosic Biomass.

Journal of fungi (Basel, Switzerland), 11(6): pii:jof11060458.

Microbial decomposition of persistent natural compounds such as phenolic lignin and polysaccharides in plant cell walls plays a crucial role in the global carbon cycle and underpins diverse biotechnological applications. Among microbial decomposers, fungi from the Ascomycota and Basidiomycota phyla have evolved specialized mechanisms for efficient lignocellulosic biomass degradation, employing extracellular enzymes and synergistic fungal consortia. Fungal coculture, defined as the controlled, axenic cultivation of multiple fungal species or strains in a single culture medium, is a promising strategy for industrial processes. This approach to biomass conversion offers potential for enhancing production of enzymes, biofuels, and other high-value bioproducts, while enabling investigation of ecological dynamics and metabolic pathways relevant to biorefinery operations. Lignocellulosic biomass conversion into fuels, energy, and biochemicals is central to the bioeconomy, integrating advanced biotechnology with sustainable resource use. Recent advancements in -omics technologies, including genomics, transcriptomics, and proteomics, have facilitated detailed analysis of fungal metabolism, uncovering novel secondary metabolites and enzymatic pathways activated under specific growth conditions. This review highlights the potential of fungal coculture systems to advance sustainable biomass conversion in alignment with circular bioeconomy goals.

RevDate: 2025-06-25

Lingua MS, Sabatino ME, Cuatrin A, et al (2025)

From waste to worth: stability, bioaccessibility, and cellular antioxidant activity of microencapsulated red grape pomace phenolics.

Journal of the science of food and agriculture [Epub ahead of print].

BACKGROUND: Red grape pomace (RGP) is a recognized winery by-product due to its phenolic profile with valuable antioxidant power and beneficial health properties. Following the latest trends in food science and technology, this study valorizes the use of RGP to obtain a food ingredient rich in antioxidant phenolics. An integrated approach was proposed, investigating the production by spray drying of easy-to-handle microparticles, rich in stable compounds with antioxidant properties demonstrated after simulated digestion using in vitro assays and Caco-2 cells. The changes in microbiota composition after fermentation were also studied.

RESULTS: Among investigated wall materials, maltodextrin/skimmed milk powder (1:1) 300 g L[-1] offered the highest drying yield, appropriate moisture, solubility, and adequate microparticle morphology, as well as the best stability of polyphenols. Encapsulation improved the protection of phenolic compounds and the in vitro antioxidant capacity during 120 days of storage at 4 and 25 °C, as compared to those unencapsulated. Microencapsulated polyphenols bioaccessibility was evident in 15 out of 22 compounds initially quantified, with 6.6% potentially absorbed. The polyphenols from microcapsules modulated positively the microbial ecology after colonic fermentation. Those derived from intestinal digestion demonstrated the highest capacity to reduce the reactive oxygen species under oxidative stress conditions in Caco-2 cells.

CONCLUSION: RGP could be used in the development of new food ingredients as a potential candidate for health promotion. This represents the first report on the benefits of RGP microcapsules as a food ingredient, validating its final biological effects in a cellular model considering the processing and digestion effects. © 2025 Society of Chemical Industry.

RevDate: 2025-06-25

Klein ML, Erikson CB, McCabe CJ, et al (2025)

Limited effects of tannin supplementation on the dairy cattle fecal microbiome with modulation of metabolites.

Frontiers in microbiology, 16:1570127.

Tannins are plant secondary metabolites that bind organic carbon (C) and nitrogen (N), potentially altering substrate bioavailability for enteric fermentation in ruminants. This interaction may reduce greenhouse gas (GHG) emissions and influence nitrogen partitioning. Given tannins' resistance to ruminal degradation and persistence through the gastrointestinal tract, this study investigated the effects of a tannin-based feed additive on fecal microbial diversity, fecal chemical composition, and GHG emissions. Twenty-four early- to mid-lactation dairy cows were randomized to receive either a tannin-based feed additive (TRT; containing condensed and hydrolyzable tannins from Schinopsis quebracho-colorado [Schltdl.]) or a control diet (CON) for 64 days. Cows were blocked by parity, dry matter intake, milk yield, body weight, and days in milk. Fecal samples were collected on days 0, 16, 32, and 64 and analyzed using 16S rRNA gene amplicon sequencing. Fecal C, N, and indole-3-lactate were measured, and GHG emissions (N2O, CH4, CO2) were assessed via 14-day laboratory incubation. A total of 1,538 amplicon sequence variants were identified, with Firmicutes as the dominant phylum. Fecal phylogenetic diversity showed a significant treatment × day interaction (p < 0.01), with TRT cows exhibiting reduced microbial diversity from day 16 to 64. Fecal C and N concentrations were significantly lower (p < 0.01) in TRT cows on day 16, while indole-3-lactate levels were higher on day 64 (p = 0.02). GHG emissions did not differ significantly between treatments. The tannin-based feed additive influenced fecal microbial community structure and select chemical parameters but did not significantly affect GHG emissions from feces. These findings suggest that dietary tannins may modulate gut microbial ecology with minimal impact on downstream manure-related emissions.

RevDate: 2025-06-25

Long Y, Li Y, Zhang J, et al (2025)

Unconventional Nitrogen Fixation and Adaptive Genomics of a New Neorhizobium glycines sp. nov., A Promising Soybean Symbiont.

Plant, cell & environment [Epub ahead of print].

RevDate: 2025-06-24
CmpDate: 2025-06-24

McGrath AH, Steinberg PD, Egan S, et al (2025)

Disruption of host-associated and benthic microbiota affects reproductive output and settlement of a habitat-forming macroalga.

Proceedings. Biological sciences, 292(2049):20250729.

The reproduction and establishment of habitat-forming species are key processes affecting their persistence and associated biodiversity. In marine systems, microbial communities associated with habitat-forming macroalgae can influence various aspects of host performance; however, the role of these microorganisms in influencing macroalgal reproduction and settlement is poorly understood. Using a dominant habitat-forming macroalga on Australian rocky shores, Hormosira banksii, we manipulated host- and benthic-associated microbiota to determine the relative importance of microorganisms to reproductive output (number of viable eggs released) and settlement (settlement and morphogenesis of algal zygotes). Disruption of the host microbiota using antibiotics decreased reproductive output after 2 weeks, with the effect dependent on the type of antibiotic used. Disruption of host- and benthic-associated microbiota, in combination, caused a significant decrease in settlement of H. banksii zygotes, with the combined disruption having the greatest impact on settlement success. Our results demonstrate the importance of host-associated microbiota in macroalgal reproduction and an interactive effect of host- and benthic-associated microbiota on settlement-a key ecological process with important implications for host fitness and potentially ecosystem persistence.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Bota JL, Baum C, Gawronski S, et al (2025)

UV treatment of the digestive fluid of Nepenthes hemsleyana pitcher plants affects their digestive process, possibly via reducing microbial inquilines.

Oecologia, 207(7):108.

Interactions with microbes are ubiquitous, and many of them are essential for the survival and success of plants. In Nepenthes pitcher plants, they occur as part of a diverse community of organisms, so-called inquilines, that live inside the digestive fluid of the pitcher traps. However, evidence is ambiguous regarding the role of microbial inquilines: they may complement the plants' prey digestion, fix atmospheric N, act as competitors that reduce plant-available nutrients or affect the plants in other ways unrelated to the breakdown of prey. In a field experiment on Borneo, we investigated the effect of UV disinfection of the digestive fluid on prey digestion of N. hemsleyana that captures and digests insects as well as bat faeces in its pitchers. We show that in the short term, the photosynthetic performance of plants with UV-treated digestive fluids decreases compared to untreated plants, likely due to lower abundances of microbial inquilines. However, at the end of 2 months, responses of pitcher plants with UV-treated and untreated digestive fluids tend to equalise. Nutrient source, whether from insects or bat faeces, does not influence prey digestion. We expect our findings to be a starting point for unveiling the ecological role of microbial inquilines in pitcher plants and how they interact with other inquiline groups of higher trophic levels. Ultimately, this will also help to improve understanding of the functioning and evolution of convergent interactions in other carnivorous plants.

RevDate: 2025-06-24

Wu BX, Ma JY, Huang XC, et al (2025)

Acupuncture as A Potential Therapeutic Approach for Tourette Syndrome: Modulation of Neurotransmitter Levels and Gut Microbiota.

Chinese journal of integrative medicine [Epub ahead of print].

OBJECTIVE: To investigate the effects of acupuncture on the neurotransmitter levels and gut microbiota in a mouse model of Tourette syndrome (TS).

METHODS: Thirty-six male C57/BL6 mice were randomly divided into 4 groups using a random number table method: 3,3'-iminodipropionitrile (IDPN) group, control group, acupuncture group, and tiapride group, with 9 mice in each group. In the IDPN group, acupuncture group, and tiapride group, mice received daily intraperitoneal injections of IDPN (300 mg/kg body weight) for 7 consecutive days to induce stereotyped behaviors. Subsequently, in the acupuncture intervention group, standardized acupuncture treatment was administered for 14 consecutive days to IDPN-induced TS model mice. The selected acupoints included Baihui (DU 20), Yintang (DU 29), Waiguan (SJ 5), and Zulinqi (GB 41). In the tiapride group, mice were administered tiapride (50 mg/kg body weight) via oral gavage daily for 14 consecutive days. The control group, IDPN group, and acupuncture group received the same volume of saline orally for 14 consecutive days. Stereotypic behaviors were quantified through behavioral assessments. Neurotransmitter levels, including dopamine (DA), glutamate (Glu), and aspartate (ASP) in striatal tissue were measured using enzyme-linked immunosorbent assay. Dopamine transporter (DAT) expression levels were additionally quantified through quantitative polymerase chain reaction (qPCR). Gut microbial composition was analyzed through 16S ribosomal RNA gene sequencing, while metabolic profiling was conducted using liquid chromatography-mass spectrometry (LC-MS).

RESULTS: Acupuncture administration significantly attenuated stereotypic behaviors, concurrently reducing striatal levels of DA, Glu and ASP concentrations while upregulating DAT expression compared with untreated TS controls (P<0.05 or P<0.01). Comparative analysis identified significant differences in Muribaculaceae (P=0.001), Oscillospiraceae (P=0.049), Desulfovibrionaceae (P=0.001), and Marinifilaceae (P=0.014) following acupuncture intervention. Metabolomic profiling revealed alterations in 7 metabolites and 18 metabolic pathways when compared to the TS mice, which involved various amino acid metabolisms associated with DA, Glu, and ASP.

CONCLUSIONS: Acupuncture demonstrates significant modulatory effects on both central neurotransmitter systems and gut microbial ecology, thereby highlighting its dual therapeutic potential for TS management through gut-brain axis regulation.

RevDate: 2025-06-23

Mattelin V, Van Landuyt J, Kerkhof F-M, et al (2025)

Integrating taxonomic and phenotypic information through FISH-enhanced flow cytometry for microbial community dynamics analysis.

Microbiology spectrum [Epub ahead of print].

UNLABELLED: Flow cytometry is a powerful tool to monitor microbial communities, as it allows tracking both changes in the subpopulations and cell numbers at high throughput and a low sample cost. This information can be combined in a phenotypic fingerprint that can be leveraged for diversity analysis. However, as isogenic individuals can manifest phenotypic diversity, for example, due to differing physiological state and phenotypic plasticity, combining the phenotypic information with taxonomic information adds an extra dimension for describing the dynamics of a microbial community. In this research, taxonomic information was incorporated in the microbial fingerprint through fluorescent in situ hybridization (FISH) at a single-cell level. To validate this concept and explore its versatility, two ecosystems with different micro-biodiversity were considered. In the first environment, marine bacteria were monitored for plastic biodegradation in a trickling filter, and in the second, an in vitro simulated human gut microbiome was followed over time. Samples were prepared using different (staining) methods, including FISH, and beta diversity analysis was used to evaluate the level of distinction between differently treated groups in both environments. As a reference to correlate increased distinction with the incorporation of taxonomic information, 16S rRNA gene sequencing was used. Finally, a predictive algorithm was trained to correctly classify samples in the differently treated groups. The results showed that the implementation of FISH in flow cytometry provides more information on a single-cell level to answer specific scientific questions, like distinguishing between phenotypically similar communities or following a specific taxonomic group over time.

IMPORTANCE: Understanding microbial communities is crucial for elucidating their role in maintaining ecosystem health and stability. Researchers are increasingly interested in studying microbial communities by looking at not just their genetic makeup but also their physical traits and functions. In our study, we used common techniques like fluorescence in situ hybridization and flow cytometry, along with advanced data analysis, to better understand these communities. This combination allowed us to gather and use data more effectively, demonstrating that these easy-to-use methods, when paired with proper analysis, can enhance our understanding of changing microbial ecosystems.

RevDate: 2025-06-23

VanWallendael A, Wijewardana C, Bonnette J, et al (2025)

Local adaptation of both plant and pathogen: an arms-race compromise in switchgrass rust.

The New phytologist [Epub ahead of print].

In coevolving species, parasites locally adapt to host populations as hosts locally adapt to resist parasites. Parasites often outpace host local adaptation since they have rapid life cycles, but host diversity, the strength of selection, and external environmental influence can result in complex outcomes. To better understand local adaptation in host-parasite systems, we examined locally adapted switchgrass (Panicum virgatum), and its leaf rust pathogen (Puccinia novopanici) across a latitudinal range in North America. We grew switchgrass genotypes in 10 replicated multiyear common gardens, measuring rust severity from natural infection in a 'host reciprocal transplant' framework for testing local adaptation. We conducted genome-wide association mapping to identify genetic loci associated with rust severity. Genetically differentiated rust populations were locally adapted to northern and southern switchgrass, despite host local adaptation to environmental conditions in the same regions. Rust resistance was polygenic, and distinct loci were associated with rust severity in the north and south. We narrowed a previously identified large-effect quantitative trait locus for rust severity to a candidate YELLOW STRIPE-LIKE gene and linked numerous other loci to defense-related genes. Overall, our results suggest that both hosts and parasites can be simultaneously locally adapted, especially when parasites impose less selection than other environmental factors.

RevDate: 2025-06-23

Zhang W, Li XJ, Liu F, et al (2025)

Fungen: clustering and correcting long-read metatranscriptomic data for exploring eukaryotic microorganisms.

Science China. Life sciences [Epub ahead of print].

Long-read metatranscriptomics is a powerful and cost-effective technology for elucidating the genetic diversity and expression dynamics of active eukaryotic microorganisms by characterizing full-length transcripts. However, its potential has been limited by the lack of high-quality reference genomes and high sequencing error rates. We present Fungen, a reference-free tool that constructs accurate transcripts from long-read metatranscriptomic data through read clustering and error correction. Fungen achieves superior accuracy in transcript determination while significantly reducing memory usage and offering a 22 to 56-fold speed improvement over existing methods. This novel approach overcomes the challenges posed by sequence similarity among closely related species, enabling the analysis of deeply sequenced metatranscriptomes by generating reliable gene clusters and accurate sequences. Two applications showcase Fungen's capabilities to perform high-resolution taxonomic assignments and gene profiling in marine direct RNA datasets, as well as resolving reliable annotation identities in full-length rRNA targeted sequencing datasets. When applied to soil metatranscriptomic data, Fungen offers valuable insights into the in situ fungal composition and gene expression dynamics, revealing specialized life strategies of plant-pathogenic fungi in soil environments. Overall, Fungen provides a fast, scalable, and accurate solution for analyzing complex metatranscriptomic datasets, paving the way for a comprehensive understanding of eukaryotic diversity and function from long-read sequencing data.

RevDate: 2025-06-23

Susukida S, Miyazawa K, Ichikawa H, et al (2025)

Improved Mixing Properties of Stirred Fermentation of an Aspergillus oryzae Hyphal Dispersion Mutant.

Biotechnology and bioengineering [Epub ahead of print].

The complexity of mechanical and biological processes in filamentous fungal fermentation remains a major obstacle to improving product yield. We previously demonstrated that the AGΔ-GAGΔ strain of Aspergillus oryzae, lacking both α-1,3-glucan (AG) and galactosaminogalactan (GAG), had improved hyphal dispersion, reduced culture viscosity, and increased recombinant protein production. Here, we applied computational fluid dynamics (CFD) and multi-omics analysis to characterize the AGΔ-GAGΔ strain during fermentation in a stirred-tank bioreactor. CFD simulations revealed large gas cavities behind the impeller blades and severe compartmentalization in both wild-type and AGΔ-GAGΔ cultures. However, shear stress distribution was broader and gas cavity formation was lower in the AGΔ-GAGΔ strain than in the wild type. The simulation results were consistent with measurements of volumetric oxygen mass transfer coefficients (KLa) and mixing times. Transcriptome analysis revealed upregulation of TCA-cycle genes in AGΔ-GAGΔ relative to the wild type. Analysis of intracellular and extracellular metabolites indicated distinct metabolic profiles associated with oxygen availability. Our findings highlight the critical role of hydrodynamics in fungal fermentation and demonstrate the potential of strain engineering for improving mixing characteristics.

RevDate: 2025-06-23

Noviello D, Amoroso C, Vecchi M, et al (2025)

Curing inflammatory bowel diseases: breaking the barriers of current therapies- emerging strategies for a definitive treatment.

Current opinion in immunology, 95:102593 pii:S0952-7915(25)00069-X [Epub ahead of print].

Chronic intestinal inflammation in inflammatory bowel diseases (IBD) reflects the interplay of genetic predisposition, immune dysregulation, microbial imbalance, and epithelial barrier defects. Current therapies for IBD primarily focus on controlling inflammation necessitating lifelong treatment and face a 'therapeutic ceiling' due to primary and secondary loss of efficacy over time. Immune-mediated approaches do not address additional pathogenic mechanisms, such as impairment of epithelial barrier and gut microbial ecology. Thus, innovative strategies are required to foster the field closer to a definitive cure. This review discusses novel strategies to overcome current therapeutic limitations, including immune reset via hematopoietic stem cell transplantation and B cell-targeted therapies, antigen-specific interventions such as chimeric antigen receptor T cells and tolerogenic vaccines, and intestinal epithelial barrier restoration. We also explore microbiota-based strategies - ranging from fecal microbiota transplantation to engineered consortia and bacteriophages - and discuss the adjunctive role of diet. Together, we outline a potential research roadmap toward a potential cure for IBD.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Woods PH, Speth DR, Laso-Pérez R, et al (2025)

Identification of key steps in the evolution of anaerobic methanotrophy in Candidatus Methanovorans (ANME-3) archaea.

Science advances, 11(25):eadq5232.

Despite their large environmental impact and multiple independent emergences, the processes leading to the evolution of anaerobic methanotrophic archaea (ANME) remain unclear. This work uses comparative metagenomics of a recently evolved but understudied ANME group, "Candidatus Methanovorans" (ANME-3), to identify evolutionary processes and innovations at work in ANME, which may be obscured in earlier evolved lineages. We identified horizontal transfer of hdrA homologs and convergent evolution in carbon and energy metabolic genes as potential early steps in Methanovorans evolution. We also identified the erosion of genes required for methylotrophic methanogenesis along with horizontal acquisition of multiheme cytochromes and other loci uniquely associated with ANME. The assembly and comparative analysis of multiple Methanovorans genomes offers important functional context for understanding the niche-defining metabolic differences between methane-oxidizing ANME and their methanogen relatives. Furthermore, this work illustrates the multiple evolutionary modes at play in the transition to a globally important metabolic niche.

RevDate: 2025-06-24

Zhang Z, Shi Z, Zheng L, et al (2025)

Remediation of acetochlor-contaminated maize field soil using Serratia odorifera AC-1 fertilizer: effects on soil microbial communities.

Frontiers in microbiology, 16:1510157.

Acetochlor is a chloroacetamide herbicide that is widely applied in corn fields. Nevertheless, the long-term usage of acetochlor in the soil leads to residues, which severely affect the germination of corn seeds and the growth of seedlings, and even exert an influence on the soil microbial community. Microbial degradation of acetochlor is the principal approach for restoring the soil microbial ecology. In this study, the Serratia odorifera AC-1 strain was isolated and identified from the soil for the degradation of residual acetochlor in the soil. To enhance the degradation efficiency, a solid microbial agent was prepared by using activated carbon as a carrier and the AC-1 strain at a 1:1 ratio and applied to the soil for degradation and remediation experiments. The content of the microbial cells in the solid microbial agent was 1.49 × 106 CFU/g after 120 days of preparation. The application of the AC-1 solid microbial agent significantly influenced the relative abundance of soil microbial communities (Actinobacteria, Firmicutes, and Proteobacteria), increasing the diversity of bacterial populations in the soil. The experimental results indicated that after the application of the AC-1 solid microbial agent, the plant height, stem diameter, and photosynthetic efficiency of corn seedlings under acetochlor stress were significantly elevated. When the application rate of the AC-1 solid microbial agent was 5.00 mg/kg, the stem diameter of corn increased by 56.4% compared with the control group. When the acetochlor concentration in the soil was 6.65 mg/kg, the DT50 value of the AC-1 solid microbial agent was 2.28 days. This study clarified the degradation mechanism and remediation capacity of the Serratia odorifera AC-1 strain in acetochlor-contaminated soil and proposed a new strategy to improve the stability and degradation efficiency of the microbial strain by optimizing the immobilization technology of the strain on activated carbon. This research provides a scientific basis and technical guidance for the future application of bioremediation technology in the field environment to remove pesticide residues, restore soil health, and enhance crop productivity.

RevDate: 2025-06-24
CmpDate: 2025-06-23

Embury EL, AL Romero-Olivares (2025)

Fungi Follow Flora, Bacteria Track the Seasons: A Tale of a Changing Landscape.

Microbial ecology, 88(1):68.

Microbes play critical roles in dryland ecosystems, driving nutrient cycling, soil stability, and plant interactions. Despite their ecological importance, few studies have examined how microbial communities respond to vegetation changes in arid landscapes. In the northern extent of the Chihuahuan Desert, the encroachment of woody shrubs into grasslands has been occurring since the 1800s, largely driven by extensive livestock grazing and increased drought levels. In this study, we investigated how microbial communities respond to both biotic (i.e., vegetation) and abiotic (i.e., seasonality) factors, how they assemble in a changing landscape, and which taxa may be particularly responsive to shrub encroachment or even facilitating this transformation. We assessed microbial communities using soil surface samples across five distinct seasonal periods in a grassland-to-shrubland gradient in the Jornada Experimental Range in the Chihuahuan Desert through the use of phospholipid fatty-acid analysis and DNA metabarcoding techniques. Our findings reveal that bacterial and fungal biomass are significantly influenced by seasonal changes, with strong correlations to humidity and temperature fluctuations. We also found that fungal community assembly and diversity were highly impacted by vegetation whereas seasons were more impactful on bacteria. Our results support the idea that microbes may be playing a crucial role in facilitating the grassland-to-shrubland transition. Overall, our study highlights the complex interactions between microbial communities and biotic and abiotic factors in dryland systems. These findings are essential for understanding the future of dryland ecosystems undergoing shrub encroachment and provide a critical foundation for guiding restoration efforts, particularly those looking to incorporate microbial-mediated solutions.

RevDate: 2025-06-22
CmpDate: 2025-06-19

Parret L, Simoens K, Horemans B, et al (2025)

Establishing a co-culture aggregate of N-cycle bacteria to elucidate flocculation in biological wastewater treatment.

Applied microbiology and biotechnology, 109(1):149.

Biological flocculation is a complex phenomenon that is often treated as a black box. As a result, flocculation problems are usually remediated without knowledge of the exact causes. We show that it is feasible to exploit a model (N-cycle) consortium with reduced complexity to fundamentally study bioflocculation. Strong nitrifier microcolonies were formed during oxic/anoxic cycles in sequencing batch reactors, using alginate entrapment as a cell retention system. After the release of these aggregates into suspension, macroclusters with flocs of the denitrifier were observed. These results suggest that a living model of a full-scale activated sludge floc can be built through the use of this bottom-up approach. By eliminating shifts in the microbial community, the applied experimental conditions have a more direct effect on the observations. Key Points ∙ Studying flocculation with a model consortium is feasible ∙ Alginate entrapment leads to strong microcolony formation of nitrifiers ∙ FISH by itself is not suitable to study aggregation of a coculture.

RevDate: 2025-06-23
CmpDate: 2025-06-19

Timmis K, Williams P, Karahan ZC, et al (2025)

Journals Operating Predatory Practices Are Systematically Eroding the Science Ethos: A Gate and Code Strategy to Minimise Their Operating Space and Restore Research Best Practice.

Microbial biotechnology, 18(6):e70180.

Scientific research seeks to extend knowledge and understanding, an activity that perhaps more than any other advances society and humanity. In essence, it is the search for truth. But, because it seeks new knowledge, there is little or no benchmark for appraisal of the plausibility or validity of the immediate conclusions drawn from new information gained, no instant confirmation. For this and other reasons, the science ethos requires the highest level of rigour to ensure the highest level of probability that new findings are true, or at least the most plausible under the prevailing circumstances and state of knowledge. Research is only as good as its degree of rigour. Rigour comes through intensive and comprehensive scientific training and mentoring that teaches critical and agnostic evaluation of new results, self-scrutiny and self-criticism. Additional rigour comes via independent scrutiny and validation: peer review of results and interpretations submitted as publications, and peer repetition of key experiments. However, the current proliferation of publication vehicles whose business model is based on maximisation of papers published, and the revenue stream of article processing charges (APCs) they generate, is promoting an insidious degradation of rigour and quality standards of reviewing-editing practices. Such predatory practices result in the systematic degradation of research quality and its "truthfulness". Moreover, they undermine the science ethos and threaten to create a new generation of scientists that lack this ethos. These trends will inevitably progressively erode public trust in scientists and the research ecosystem. This Editorial is a call for action to all actors, in particular leaders, in scientific research to oppose predatory practices in science dissemination-to restrict the operational space of those responsible for such practices-in order to restore and maintain research rigour and the science ethos and to prevent a downward spiral of research quality. It proposes two linked actionable solutions to the problem, one for the "pull" element of predatory practices and one for the "push" element of research ecosystem management practices, especially those promoting the publish or perish mentality, that drive authors to publish in journals with predatory practices. To counter the "pull", we propose a solution based on the principle of prevention, rather than cure, and list a number of essential policy decisions and actions that should be taken at all levels of the science chain/cloud to achieve this. A central plank of the concept is journal accreditation, without which a journal would be ineligible for payment of APCs from public funds. For accreditation, a journal would need to convincingly demonstrate adoption of a prescribed journal code of conduct. Ideally, accreditation would also be required for inclusion in journal indexing and ranking services and bibliographic databases. To counter the "push", we propose a top-down imposition of a cultural change in science management that ensures merit-based success of scientists and their careers, research best practice, improved education and mentoring of younger scientists in the science ethos and greater support of them in their careers. This must include explicit recognition of the crucial role of peer reviewing for the good health of the research enterprise, its incentivisation and appropriate appreciation of the time and effort involved. To orchestrate this change, we propose the creation of a multi-stakeholder alliance whose brief is to develop the framework and implementation strategy for changes in the research ecosystem. This Editorial also exhorts all actors to embrace the principle of publish less, publish better and to use public funding provided by tax revenues more effectively to perpetually raise the bar of science quality, dissemination and potential to advance humanity.

RevDate: 2025-06-20

Hodgson RJ, Cando-Dumancela C, Liddicoat C, et al (2025)

Strong Host Modulation of Rhizosphere-to-Endosphere Microbial Colonisation in Natural Populations of the Pan-Palaeotropical Keystone Grass Species, Themeda triandra.

Ecology and evolution, 15(6):e71595.

Soil microbiota can colonise plant roots through a two-step selection process, involving recruitment of microbiota first from bulk soil into plant rhizospheres, then into root endospheres. This process is poorly understood in all but a few model species (e.g., Arabidopsis), which is surprising given its fundamental role in plant and soil ecology. Here, we examined the microbial community assembly processes across the rhizospheres and root endospheres in eight natural populations of the pan-palaeotropical C4 grass, Themeda triandra, in southern Australia. Using a space-for-time substitution approach, we assessed whether bacterial root colonisation patterns conformed to the two-step model and tested whether community assembly was driven more by deterministic or stochastic processes. Our results show that the two-step selection process shaped bacterial recruitment dynamics across these natural T. triandra populations, and we provide clear evidence that host plants influence microbial assembly via deterministic pressures that produce strong community convergence within endospheres. These findings highlight the central role of host filtering in shaping a conserved 'core' endosphere microbiome. However, limited understanding of these endosphere communities constrains efforts to harness these important relationships to, for example, improve plant propagation and revegetation practices.

RevDate: 2025-06-21
CmpDate: 2025-06-18

Rios-Reyes A, Gonzalez-Lozano KJ, Cabral-Miramontes JP, et al (2025)

Exploration of Plant and Microbial Life at "El Chichonal" Volcano with a Sustainable Agriculture Prospection.

Microbial ecology, 88(1):67.

Active volcanic environments represent extreme habitats with underexplored potential for microbial bioprospecting. This study aimed to characterize pioneer vegetation and associated microbial diversity in the crater of "El Chichonal" volcano, with an emphasis on their potential applications in sustainable agriculture. A physicochemical analysis of the soil was performed, identifying acidic and nutrient-poor conditions. Three pioneer plant species were described: Tibouchina longifolia (dominant) and Poaceae spp. (co-dominant), and Palhinhaea cernua (non-dominant). A total of 311 microorganisms were predominantly bacteria, were isolated from soil, root, stem, and water samples. Bacillus cereus and Priestia megaterium were molecularly identified, and in vitro assays demonstrated their ability to fix nitrogen, produce auxins, and antagonize fungal pathogens (Alternaria solani, Botrytis cinerea, and Colletotrichum gloeosporioides). These results suggest that microorganisms adapted to extreme volcanic environments could be promising sources of plant growth-promoting bacteria (PGPB) with application in biological control.

RevDate: 2025-06-21

Wollrab S, Schmidt SR, Woodhouse J, et al (2025)

Fifty years of limnological data on Lake Stechlin, a temperate clearwater lake.

Scientific data, 12(1):1028.

We present 50 years of monitoring data on water quality of Lake Stechlin, a deep, dimictic hardwater lake in northeastern Germany known for its exceptionally clear water. Although located in a forested catchment, the lake has undergone major changes in recent decades, including a period of massive heating of surface water when receiving cooling water from a nearby nuclear power plant (1966-1990), accompanied by a greatly shortened water residence time from more than 40 years to less than 300 days. These changes are superimposed by a long-term trend of surface water warming and a concomitant decrease in winter ice cover. Total phosphorus concentrations have quadrupled since 2010 and zones of deep-water oxygen depletion have greatly expanded. The presented dataset covers basic water-chemical and physical records taken at monthly to fortnightly intervals from 1970 to 2020, documenting limnological changes during that period. Furthermore, it serves as a valuable basis to assess and project potential consequences of climate change and other types of environmental change on deep clearwater lakes in temperate climates.

RevDate: 2025-06-18
CmpDate: 2025-06-18

Phithakrotchanakoon C, Kitikhun S, Siriarchawatana P, et al (2025)

Flavobacterium mekongense sp. nov., isolated from the Mekong River in Thailand.

International journal of systematic and evolutionary microbiology, 75(6):.

Two Gram-stain-negative, aerobic, non-motile, non-gliding, rod-shaped bacterial strains, designated as TBRC 19031[T] and TBRC 19032, were isolated from water samples collected from the Mekong River, Thailand. Strain TBRC 19031[T] was obtained from Chiang Saen in the upstream section near the borders with China and Myanmar, while TBRC 19032 originated from Khong Chiam, in the downstream section where the river exits Thailand. Colonies of both strains were circular, smooth and deep yellow on Reasoner's 2A agar and did not produce flexirubin-type pigments. Phylogenetic analysis with 16S rRNA gene sequences placed both strains within the genus Flavobacterium, showing the highest sequence similarity to Flavobacterium cheonhonense ARSA-15[T] (98.29% for TBRC 19031[T] and 98.22% for TBRC 19032). However, whole-genome comparisons between the strains and F. cheonhonense ARSA-15[T] revealed average nt identity (89.39% and 89.29%), average aa identity (92.84% and 92.95%) and digital DNA-DNA hybridization (35.00% and 34.70%). The predominant fatty acids were iso-C15:1, iso-C15:0 and iso-C15:0 3-OH, and menaquinone MK-6 was the major respiratory quinone. The major polar lipids of both strains included phosphatidylethanolamine, steryl ester and diacylglycerol. The genome sizes were 3.02 and 3.04 Mbp, with G+C contents of 38.3% and 38.2% for TBRC 19031[T] and TBRC 19032, respectively. Comparative genomic analyses revealed the absence of genes involved in sulphate reduction and denitrification pathways and the presence of a gene encoding phosphatidylinositol synthase, distinguishing them from other Flavobacterium within the clade. Ecological profiling using public metagenomic datasets showed that both strains were associated with lotic freshwater environments. This study not only introduces Flavobacterium mekongense sp. nov. as a new species but also provides broader insights into the ecology, metabolism and environmental distribution of freshwater Flavobacterium. The genomic features identified here offer promising leads for future studies in microbial ecology, comparative genomics and functional gene mining in aquatic ecosystems. The type strain is TBRC 19031[T] (TBRC 19031[T]=NBRC 117006[T]).

RevDate: 2025-06-20
CmpDate: 2025-06-18

Bou Orm E, Mukherjee S, Rifa E, et al (2025)

Enhancing Biodiversity-Function Relationships in Field Retting: Towards Key Microbial Indicators for Retting Control.

Environmental microbiology reports, 17(3):e70102.

Hemp field retting is a bioprocess that facilitates fibre extraction by degrading pectin and other matrix components surrounding fibre bundles. However, traditional methods rely on empirical practices, often resulting in inconsistent fibre quality. This study investigates the biodiversity-function relationship in the hemp retting ecosystem to identify microbial and enzymatic indicators for improved process control. Over six weeks of field retting, we monitored bacterial and fungal community dynamics using high-throughput sequencing and assessed enzymatic activity profiles. Our results revealed a sequential enzymatic pattern: pectinases (e.g., polygalacturonase) dominated early stages, followed by hemicellulases (β-xylosidase, β-galactosidase), and later cellulases. These enzymatic shifts were reflected in the changes in microbial community composition, with pectinolytic bacteria (e.g., Proteobacteria) dominating the initial phases and cellulolytic fungi (e.g., Ascomycota) becoming more prevalent later. Our results identified specific microbial taxa correlated with optimal retting, suggesting their potential as bioindicators for monitoring retting. Specifically, key bacterial genera such as Pseudomonas and Sphingomonas, and fungal genera like Cladosporium, were associated with distinct enzymatic profiles. Our findings offer new insights into the microbial ecology of retting, providing both microbial and enzymatic indicators that could inform the development of monitoring strategies for process control, ultimately contributing to more consistent hemp fibre production.

RevDate: 2025-06-24

Akdur Öztürk E, Guadano-Procesi I, Figueiredo AM, et al (2025)

A protocol for mapping Blastocystis epidemiology and diagnostics from One Health perspective.

Open research Europe, 5:133.

Blastocystis is a globally prevalent gut protist colonising over a billion people worldwide, yet its epidemiology, transmission dynamics, and clinical significance remain underexplored. This protocol represents the first step of a large-scale effort to map Blastocystis epidemiology and diagnostic practices across Europe through the COST Action CA21105: Blastocystis under One Health. By assessing diagnostic methodologies across clinical, veterinary, and environmental sectors, this work sets the foundation for future research and standardisation. Here, we highlight key findings, challenges, and a roadmap for improving Blastocystis detection, ultimately influencing global health policies and microbial ecology studies.

RevDate: 2025-06-20

Wu WJ, Wang K, Yang YV, et al (2025)

Identification of neuronal synapse-related signatures and potential therapeutic drugs in colorectal cancer based on machine learning algorithms and molecular docking.

Translational cancer research, 14(5):2737-2757.

BACKGROUND: Nervous system-cancer interactions can regulate tumorigenesis, invasion, and metastasis. However, specific biomarkers for targeting neuron synapse in colorectal cancer (CRC) remain unexplored. This study aims to develop a neuronal synapse-related signature (NSRS) to predict survival in CRC patients, identify potential therapeutic drugs, and explore its clinical applications.

METHODS: We collected neuronal synapse genes (NSGs) from the Molecular Signatures Database (MSigDB) and published mass spectrometry data. Using weighted gene co-expression network analysis (WGCNA) and least absolute shrinkage and selection operator Cox regression (LASSO-Cox), we identified prognostic NSGs and constructed a NSRS through multivariate Cox regression. Functional enrichment analysis revealed the molecular characteristics of NSRS subgroups. Additionally, xCell and ESTIMATE algorithms quantified the abundance of 54 cell subtypes and assessed the tumor immune microenvironment (TIME) of the two NSRS subgroups. Finally, drug prediction and molecular docking identified candidate drugs with therapeutic potential.

RESULTS: Seven key prognostic NSGs were identified, and an independent, stable NSRS model was constructed. Kaplan-Meier survival curves indicated that the high NSRS group had poorer outcomes (log-rank test, P<0.05). Functional enrichment analysis revealed significant enrichment of epithelial-mesenchymal transition, hypoxia, and inflammation features in the high NSRS group. xCell and ESTIMATE analyses showed a more complex TIME and lower tumor purity in the high NSRS group, highlighting the role of neuro-tumor interactions in CRC. Drug prediction and molecular docking suggested alprostadil, dihydroergocristine, and nocodazole as candidate drugs for CRC treatment.

CONCLUSIONS: This is the first study to develop neuron synapse-related biomarkers from the perspective of neuron-cancer interactions using machine learning. We constructed a robust NSRS model and identified candidate drugs targeting prognostic NSGs, providing new insights into CRC prognosis and treatment.

RevDate: 2025-06-20

Sanz-López C, Amato M, Torrent D, et al (2025)

Microbial ecology of selected traditional Ethiopian fermented products.

Frontiers in microbiology, 16:1570914.

The consumption of traditional fermented foods and beverages plays an important role in the diet of Ethiopia, providing significant nutritional and health benefits to the local population. The present study aimed to investigate the microbial ecology and diversity of nine types of fermented products. These include two foods (Kotcho and Injera), one food condiment (Datta), and six beverages (Tej, Tella, Cheka, Kinito, Borde, and Shamita). A combination of metataxonomic and culturomic approaches was used to achieve a comprehensive characterization of the bacterial communities, together with a thorough physicochemical characterization of the fermented products. This study provides one of the most comprehensive microbial characterizations of a wide selection of Ethiopian fermented products, highlighting that some bacterial species involved in the fermentation processes could contribute to the safety and nutritional quality of fermented foods and, based on previous studies, could also play a key role in enhancing their potential probiotic properties.

RevDate: 2025-06-20

Ma R, Zhang Z, Wang J, et al (2025)

Mitigating gaseous nitrogen emissions in cotton fields through green manure and reduced nitrogen fertilization.

Frontiers in microbiology, 16:1615142.

Integrating green manure with reduced nitrogen (N) fertilization is a promising strategy to mitigate N emissions in intensive cotton cultivation, however, the underlying mechanisms remain poorly understood. This study investigated the effects of three green manure incorporation patterns-no green manure (NG), Orychophragmus violaceus (OVG), and Vicia villosa (VVG)-combined with four N reduction levels (100, 50, 25%, and conventional) on gaseous N emissions (NH3 and N2O), soil physicochemical properties, and bacterial community characteristics using a cotton field experiment in the Yellow River Basin. Results showed that OVG incorporation with 25% N reduction (N2 treatment) significantly reduced total gaseous N emissions by 36.07% on average during the cotton growth period, reducing NH3 and N2O emissions by 13.31-54.11% and 32.25-68.77%, respectively, compared with N2 application without OVG. OVG application also increased the relative abundance of Proteobacteria (28.10%), enhanced heterogeneous selection in bacterial community assembly (200%), and increased the complexity of co-occurrence networks, compared with NG. Compared with conventional N fertilization (N3 treatment), ≥50% N reduction significantly lowered NH3 (>25.51%) and N2O (>32.76%) emissions, reduced the relative abundance of Acidobacteria (-20.23%), simplified co-occurrence networks, and increased homogeneous selection in bacterial assembly (50.00%). Integrating green manure with 25% N reduction substantially reduced gaseous N emissions, which was associated with the enhanced microbial biomass carbon (MBC) and facilitated recruitment of key bacterial taxa (e.g., Sphingosinicella, Azohydromonas, Phototrophicus) within the microbial co-occurrence network. These findings provide insight into how green manure application coupled with N reduction can mitigate gaseous N losses and reshape soil microbial ecology, offering a theoretical basis for sustainable nutrient management during cotton production.

RevDate: 2025-06-18

Gao D, Guo X, Yang Z, et al (2025)

Effects of Sibiraea laevigate maxim polysaccharides on intestinal flora in immunosuppressed mice.

Journal of the science of food and agriculture [Epub ahead of print].

BACKGROUND: The intestinal microbial ecology plays a significant role in maintaining normal physiological function processes and significantly influences the immune system. However, research regarding its effects on gut flora and in vivo immunomodulation is insufficient.

RESULTS: In this study, cyclophosphamide was administered to mice to establish an immunosuppressed mouse model. The regulatory effects of Sibiraea laevigata maxim polysaccharides (SLMPs) on immunity and intestinal microbiota in the immunosuppressed mouse model were investigated. The results indicated that SLMPs could mitigate spleen and thymus damage, protect immune organs, increase the levels of leukocytes, lymphocytes, neutrophils and monocytes in mouse blood and upregulate the levels of IL-2, IFN-γ, TNF-α and IgA in mouse serum. Furthermore, SLMPs can restore intestinal microbial imbalance and enhance the diversity of gut microorganisms in immunosuppressed mice.

CONCLUSION: The findings from this study indicated that SLMPs could enhance immunity and improve the structure and abundance of intestinal flora in mice. These results provide a theoretical basis for the further development and utilization of SLMPs in immunomodulatory adjuvants and functional foods, thereby promoting their application in these fields. © 2025 Society of Chemical Industry.

LOAD NEXT 100 CITATIONS

RJR Experience and Expertise

Researcher

Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.

Educator

Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.

Administrator

Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.

Technologist

Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.

Publisher

While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.

Speaker

Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.

Facilitator

Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.

Designer

Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

Support this website:
Order from Amazon
We will earn a commission.

This book covers the ecological activities of microbes in the biosphere with an emphasis on microbial interactions within their environments and communities In thirteen concise and timely chapters, Microbial Ecology presents a broad overview of this rapidly growing field, explaining the basic principles in an easy-to-follow manner. Using an integrative approach, it comprehensively covers traditional issues in ecology as well as cutting-edge content at the intersection of ecology, microbiology,

963 Red Tail Lane
Bellingham, WA 98226

206-300-3443

E-mail: RJR8222@gmail.com

Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

short personal version

Curriculum Vitae for R J Robbins

long standard version

RJR Picks from Around the Web (updated 11 MAY 2018 )