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22 Oct 2020 at 01:31
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Bibliography on: Metagenomics


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RJR: Recommended Bibliography 22 Oct 2020 at 01:31 Created: 


While genomics is the study of DNA extracted from individuals — individual cells, tissues, or organisms — metagenomics is a more recent refinement that analyzes samples of pooled DNA taken from the environment, not from an individual. Like genomics, metagenomic methods have great potential in many areas of biology, but none so much as in providing access to the hitherto invisible world of unculturable microbes, often estimated to comprise 90% or more of bacterial species and, in some ecosystems, the bulk of the biomass. A recent describes how this new science of metagenomics is beginning to reveal the secrets of our microbial world: The opportunity that stands before microbiologists today is akin to a reinvention of the microscope in the expanse of research questions it opens to investigation. Metagenomics provides a new way of examining the microbial world that not only will transform modern microbiology but has the potential to revolutionize understanding of the entire living world. In metagenomics, the power of genomic analysis is applied to entire communities of microbes, bypassing the need to isolate and culture individual bacterial community members.

Created with PubMed® Query: metagenomic OR metagenomics OR metagenome NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)


RevDate: 2020-10-21

Velmurugan G, Dinakaran V, Rajendhran J, et al (2020)

Blood Microbiota and Circulating Microbial Metabolites in Diabetes and Cardiovascular Disease.

Trends in endocrinology and metabolism: TEM, 31(11):835-847.

Diabetes and cardiovascular disease (CVD) have evolved as the leading cause of mortality and morbidity worldwide. In addition to traditional risk factors, recent studies have established that the human microbiota, particularly gut bacteria, plays a role in the development of diabetes and CVD. Although the presence of microbes in blood has been known for centuries, mounting evidence in this metagenomic era provides new insights into the role of the blood microbiota in the pathogenesis of non-infectious diseases such as diabetes and CVD. We highlight the origin and physiology of the blood microbiota and circulating microbial metabolites in relation to the etiology and progression of diabetes and CVD. We also discuss translational perspectives targeting the blood microbiota in the diagnosis and treatment of diabetes and CVD.

RevDate: 2020-10-21

Agga GE, Silva PJ, RS Martin (2020)

Third-Generation Cephalosporin- and Tetracycline-Resistant Escherichia coli and Antimicrobial Resistance Genes from Metagenomes of Mink Feces and Feed.

Foodborne pathogens and disease [Epub ahead of print].

American mink (Neovison vison) is a significant source of global fur production. Except for a few studies from Denmark and Canada reporting antimicrobial resistance in bacteria isolated from clinical cases, studies from the general mink population are scarce and absent in the United States. Mink feces (n = 42) and feed (n = 8) samples obtained from a mink farm were cultured for the enumeration and detection of tetracycline-resistant (TETr)- and third-generation cephalosporin-resistant (TGCr)-Escherichia coli. Isolates were characterized phenotypically for their resistance to other antibiotics and genotypically for resistance genes. TETrE. coli were detected from 98% of feces samples (mean concentration = 6 log10) and from 100% of feed samples (mean concentration = 3.2 logs). Among TETrE. coli isolates, 44% (n = 41) of fecal- and 50% (n = 8) of feed isolates were multidrug resistant (MDR; resistance to ≥3 antimicrobial classes), and 96% (n = 49) of TETr isolates were positive for tet(A) and/or tet(B). TGCrE. coli were detected from 95% of feces and 75% of feed samples with 78% (n = 40) of fecal isolates, and all six of the feed isolates were MDR. Nearly two-thirds (65%) of the TGCrE. coli isolates (n = 46) were positive for blaCMY-2; the remaining 35% were positive for blaCTX-M, with the blaCTX-M-14 being the predominant (75%, n = 16) variant detected. Metagenomic DNA was extracted directly from feces and feed samples, and it was tested for 84 antimicrobial resistance genes by using quantitative polymerase chain reaction (PCR) array; selected genes were also quantified by droplet digital PCR. The genes detected from the fecal samples belonged mainly to five antimicrobial classes: macrolide-lincosamide-streptogramin B (MLSB; 100% prevalence), TETs (88.1%), β-lactams (71.4%), aminoglycosides (66.7%), and fluoroquinolones (47.6%). β-Lactam, MLSB, and TET resistance genes were also detected from feed samples. Our study serves as a baseline for further studies and to streamline antimicrobial use in mink production in accordance with current regulations as in food animals.

RevDate: 2020-10-21

Li D, Sharp JO, JE Drewes (2020)

Microbial genetic potential for xenobiotic metabolism increases with depth during biofiltration.

Environmental science. Processes & impacts, 22(10):2058-2069.

Water infiltration into the subsurface can result in pronounced biogeochemical depth gradients. In this study, we assess metabolic potential and properties of the subsurface microbiome during water infiltration by analyzing sediments from spatially-segmented columns. Past work in these laboratory set-ups demonstrated that removal efficiencies of trace organic pollutants were enhanced by limited availability of biodegradable dissolved organic carbon (BDOC) associated with higher humic ratios and deeper sediment regions. Distinct differences were observed in the microbial community when contrasting shallow versus deeper profile sediments. Metagenomic analyses revealed that shallow sediments contained an enriched potential for bacterial growth and division processes. In contrast, deeper sediments harbored a significant increase in genes associated with the metabolism of secondary metabolites and the biotransformation of xenobiotic water pollutants. Metatranscripts further supported this trend, with increased potential for metabolic attributes associated with the biotransformation of xenobiotics and antibiotic resistance within deeper sediments. Furthermore, increasing ratios of humics in feed solutions correlated to enhanced expression of genes associated with xenobiotic biodegradation. These results provide genetic support for the interplay of dissolved organic carbon limitation and enhanced trace organic biotransformation by the subsurface microbiome.

RevDate: 2020-10-21

Xie D, Xu W, Xian Y, et al (2020)

Rare case of intracranial hemorrhage associated with seoul virus infection diagnosed by metagenomic next-generation sequencing.

BACKGROUND: Seoul virus (SEOV) is a Hantavirus and the causative pathogen of Hemorrhagic Fever with Renal Syndrome (HFRS). Diagnosing SEOV infection is difficult because the clinical presentations are often undistinguishable from other viral or bacterial infections. In addition, diagnostic tools including serological and molecular assays are not readily available in the clinical settings.

CASE REPORT: A 57-year-old male presented with fever and a sudden loss of consciousness in November 2019. Computed tomography (CT) scan showed subdural hematoma, subfalcine herniation, and brain infarction. He developed thrombocytopenia and elevated transaminases, but no rashes or obvious kidney damage. He reported having a rat bite. HFRS was suspected. The Hantavirus IgG was positive, and the metagenomic next-generation sequencing (mNGS) detected SEOV sequences directly in the blood.

CONCLUSION: This report highlights the importance of suspecting SEOV infection in febrile patients with thrombocytopenia and elevated liver enzymes despite the absence of hemorrhagic manifestations of skin and renal syndromes. Next-generation sequencing is a powerful tool for pathogen detection. Intracranial hemorrhage and brain infarction as extrarenal manifestations of HFRS are rare but possible as demonstrated in this case.

RevDate: 2020-10-21

Kroeger ME, Meredith LK, Meyer KM, et al (2020)

Rainforest-to-pasture conversion stimulates soil methanogenesis across the Brazilian Amazon.

The ISME journal pii:10.1038/s41396-020-00804-x [Epub ahead of print].

The Amazon rainforest is a biodiversity hotspot and large terrestrial carbon sink threatened by agricultural conversion. Rainforest-to-pasture conversion stimulates the release of methane, a potent greenhouse gas. The biotic methane cycle is driven by microorganisms; therefore, this study focused on active methane-cycling microorganisms and their functions across land-use types. We collected intact soil cores from three land use types (primary rainforest, pasture, and secondary rainforest) of two geographically distinct areas of the Brazilian Amazon (Santarém, Pará and Ariquemes, Rondônia) and performed DNA stable-isotope probing coupled with metagenomics to identify the active methanotrophs and methanogens. At both locations, we observed a significant change in the composition of the isotope-labeled methane-cycling microbial community across land use types, specifically an increase in the abundance and diversity of active methanogens in pastures. We conclude that a significant increase in the abundance and activity of methanogens in pasture soils could drive increased soil methane emissions. Furthermore, we found that secondary rainforests had decreased methanogenic activity similar to primary rainforests, and thus a potential to recover as methane sinks, making it conceivable for forest restoration to offset greenhouse gas emissions in the tropics. These findings are critical for informing land management practices and global tropical rainforest conservation.

RevDate: 2020-10-21

Norsigian CJ, Danhof HA, Brand CK, et al (2020)

Systems biology analysis of the Clostridioides difficile core-genome contextualizes microenvironmental evolutionary pressures leading to genotypic and phenotypic divergence.

NPJ systems biology and applications, 6(1):31 pii:10.1038/s41540-020-00151-9.

Hospital acquired Clostridioides (Clostridium) difficile infection is exacerbated by the continued evolution of C. difficile strains, a phenomenon studied by multiple laboratories using stock cultures specific to each laboratory. Intralaboratory evolution of strains contributes to interlaboratory variation in experimental results adding to the challenges of scientific rigor and reproducibility. To explore how microevolution of C. difficile within laboratories influences the metabolic capacity of an organism, three different laboratory stock isolates of the C. difficile 630 reference strain were whole-genome sequenced and profiled in over 180 nutrient environments using phenotypic microarrays. The results identified differences in growth dynamics for 32 carbon sources including trehalose, fructose, and mannose. An updated genome-scale model for C. difficile 630 was constructed and used to contextualize the 28 unique mutations observed between the stock cultures. The integration of phenotypic screens with model predictions identified pathways enabling catabolism of ethanolamine, salicin, arbutin, and N-acetyl-galactosamine that differentiated individual C. difficile 630 laboratory isolates. The reconstruction was used as a framework to analyze the core-genome of 415 publicly available C. difficile genomes and identify areas of metabolism prone to evolution within the species. Genes encoding enzymes and transporters involved in starch metabolism and iron acquisition were more variable while C. difficile distinct metabolic functions like Stickland fermentation were more consistent. A substitution in the trehalose PTS system was identified with potential implications in strain virulence. Thus, pairing genome-scale models with large-scale physiological and genomic data enables a mechanistic framework for studying the evolution of pathogens within microenvironments and will lead to predictive modeling to combat pathogen emergence.

RevDate: 2020-10-21

Brinch C, Leekitcharoenphon P, Duarte ASR, et al (2020)

Long-Term Temporal Stability of the Resistome in Sewage from Copenhagen.

mSystems, 5(5):.

Antimicrobial resistance (AMR) is a major threat to global health, and it is crucial to understand the epidemiological aspects in order to predict the emergence and propagation of AMR genes. The aim of this study was to assess the variability and medium-term AMR trends within the mostly healthy human population of a single city. We monitored over 36 months (November 2015 to November 2018) the AMR level in the city of Copenhagen, Denmark, by taking bi-weekly sewage samples from the inlets of the three main water treatment plants, extracting the DNA, performing metagenomic sequencing, and read-mapping against a database of known AMR genes. We found that the AMR level was surprisingly stable with no periodic variability and no signs of drift over the measured period. We found, however, that the seemingly random variations at each site correlate in time with each other, suggesting that the variations we see are due to real environmental changes in the occurrence of AMR.IMPORTANCE The Copenhagen sewage resistome is surprisingly stable in time. The implication is that, at least for cities that are comparable to Copenhagen in terms of sewer infrastructure, few or even single samples provide a robust picture of the resistome within a city.

RevDate: 2020-10-21

Du J, Gu M, Yin Q, et al (2020)

Temporary addition of carbon fibers facilitates methanogenic degradation of ethanol during anaerobic treatment.

The Science of the total environment pii:S0048-9697(20)36253-7 [Epub ahead of print].

Syntrophic methanogenesis can be improved by the addition of conductive materials. In this study, conductive carbon fibers (CFs) were applied to efficiently enrich syntrophic microorganisms with potential direct interspecies electron transfer (DIET) ability and promote methanogenic activity. With ethanol as the substrate, CFs shortened the acclimation time remarkably. The maximum methane production rate and the ethanol degradation rate of suspended biomass were increased by 40% and 68%, respectively, even when CFs were subsequently removed. However, with acetate and propionate as the mixed substrate, CFs decreased the methanogenic activity. In the reactor fed with ethanol, CFs increased the relative abundance of Geobacter, Desulfovibrio, and methanogens by 57%, 39%, and 63%, respectively. Methanosaeta possessed most methane production genes and might involve in DIET. Furthermore, CFs increased the relative abundance of ethanol-degradation genes assigned to Geobacter, Desulfovibrio and Pelobacter, suggesting the promoted ethanol-degradation. The triggered electron transport system activity and acetoclastic methanogenesis also explained the accelerated effects on ethanol-degradation by long-term acclimation with CFs. Notably, the dominance of Geobacter and Methanosaeta combined with the increased electron transfer constant in the CFs-amended ethanol reactor indicated the potential role of DIET after the removal of CFs, which deserved further clarification.

RevDate: 2020-10-21

Bui VK, C Wei (2020)

CDKAM: a taxonomic classification tool using discriminative k-mers and approximate matching strategies.

BMC bioinformatics, 21(1):468 pii:10.1186/s12859-020-03777-y.

BACKGROUND: Current taxonomic classification tools use exact string matching algorithms that are effective to tackle the data from the next generation sequencing technology. However, the unique error patterns in the third generation sequencing (TGS) technologies could reduce the accuracy of these programs.

RESULTS: We developed a Classification tool using Discriminative K-mers and Approximate Matching algorithm (CDKAM). This approximate matching method was used for searching k-mers, which included two phases, a quick mapping phase and a dynamic programming phase. Simulated datasets as well as real TGS datasets have been tested to compare the performance of CDKAM with existing methods. We showed that CDKAM performed better in many aspects, especially when classifying TGS data with average length 1000-1500 bases.

CONCLUSIONS: CDKAM is an effective program with higher accuracy and lower memory requirement for TGS metagenome sequence classification. It produces a high species-level accuracy.

RevDate: 2020-10-21
CmpDate: 2020-10-21

Villasante A, Ramírez C, Rodríguez H, et al (2019)

In-depth analysis of swim bladder-associated microbiota in rainbow trout (Oncorhynchus mykiss).

Scientific reports, 9(1):8974 pii:10.1038/s41598-019-45451-1.

Our knowledge regarding microbiota associated with the swim bladder of physostomous, fish with the swim bladder connected to the esophagus via the pneumatic duct, remains largely unknown. The goal of this study was to conduct the first in-depth characterization of the swim bladder-associated microbiota using high-throughput sequencing of the V4 region of the 16 S rRNA gene in rainbow trout (Oncorhynchus mykiss). We observed major differences in bacterial communities composition between swim bladder-associated microbiota and distal intestine digesta microbiota in fish. Whilst bacteria genera, such as Cohnella, Lactococcus and Mycoplasma were more abundant in swim bladder-associated microbiota, Citrobacter, Rhodobacter and Clavibacter were more abundant in distal intestine digesta microbiota. The presumptive metabolic function analysis (PICRUSt) revealed several metabolic pathways to be more abundant in the swim bladder-associated microbiota, including metabolism of carbohydrates, nucleotides and lipoic acid as well as oxidative phosphorylation, cell growth, translation, replication and repair. Distal intestine digesta microbiota showed greater abundance of nitrogen metabolism, amino acid metabolism, biosynthesis of unsaturated fatty acids and bacterial secretion system. We demonstrated swim bladder harbors a unique microbiota, which composition and metabolic function differ from microbiota associated with the gut in fish.

RevDate: 2020-10-20

Sinnar SA, SJ Schiff (2020)

The Problem of Microbial Dark Matter in Neonatal Sepsis.

Emerging infectious diseases, 26(11):2543-2548.

Neonatal sepsis (NS) kills 750,000 infants every year. Effectively treating NS requires timely diagnosis and antimicrobial therapy matched to the causative pathogens, but most blood cultures for suspected NS do not recover a causative pathogen. We refer to these suspected but unidentified pathogens as microbial dark matter. Given these low culture recovery rates, many non-culture-based technologies are being explored to diagnose NS, including PCR, 16S amplicon sequencing, and whole metagenomic sequencing. However, few of these newer technologies are scalable or sustainable globally. To reduce worldwide deaths from NS, one possibility may be performing population-wide pathogen discovery. Because pathogen transmission patterns can vary across space and time, computational models can be built to predict the pathogens responsible for NS by region and season. This approach could help to optimally treat patients, decreasing deaths from NS and increasing antimicrobial stewardship until effective diagnostics that are scalable become available globally.

RevDate: 2020-10-20

Lee GE, Kim JJ, Kim HS, et al (2020)

Metagenomic analysis of the dust particles collected from the suction tube and the suction funnel of a dermatological laser smoke evacuator system.

Lasers in medical science pii:10.1007/s10103-020-03165-1 [Epub ahead of print].

In the last few decades, there has essentially been an explosion in the use of lasers in medicine, especially in the area of cosmetic dermatology. Potentially harmful substances are liberated when tissues are vaporized with laser. This creates numerous risks, including the spread of infectious disease. Smoke evacuators are devices that capture and filter laser plume, thereby maintaining a safe environment for the surgical team and patient. Our aim was to characterize the microbial community structure within the suction tube and funnel of the smoke evacuator system, identify their origin, and evaluate pathogenicity. Dust particles were collected from the instruments with a cotton swab. DNA was extracted from the swabs and the transport media, and sequencing was performed using the Illumina HiSeq Xplatform. Metagenomic analysis was conducted using the Empowering the Development of Genomics Expertise (EDGE) Bioinformatics pipeline and custom Python scripts. The most abundant bacterial species were Micrococcus luteus and Brevibacterium casei in the suction tube, and Dermacoccus sp. Ellin 185 and Janibacter hoylei in the suction funnel. A total of 15 medium- to high-quality metagenome-assembled genomes (MAGs) were constructed where we found 104 antibiotic-resistant genes (ARGs) and 741 virulence factors. Findings indicate that the suction tube and funnel are likely a reservoir of virulence factor genes and ARGs, which can possibly be passed on to other bacteria via horizontal gene transfer. We would like to emphasize the health risk these microorganisms pose and the need to reevaluate the current hygiene standards with regard to the smoke evacuator system.

RevDate: 2020-10-20

Wang JY, Li X, Chen JY, et al (2020)

Epileptic Seizure after Use of Moxifloxacin in Man with Legionella longbeachae Pneumonia.

Emerging infectious diseases, 26(11):2725-2727.

Legionellosis caused by Legionella longbeachae is diagnosed mainly by PCR. We report a case of L. longbeachae infection in mainland China, which was diagnosed by metagenomic next-generation sequencing, in a man who developed an epileptic seizure after using moxifloxacin. Metagenomic next-generation sequencing may be a useful tool to detect Legionella spp.

RevDate: 2020-10-20

Ertekin E, Meslier V, Browning A, et al (2020)

Rock structure drives the taxonomic and functional diversity of endolithic microbial communities in extreme environments.

Environmental microbiology [Epub ahead of print].

Endolithic (rock-dwelling) microbial communities are ubiquitous in hyper-arid deserts around the world and the last resort for life under extreme aridity. These communities are excellent models to explore biotic and abiotic drivers of diversity because they are of low complexity. Using high-throughput amplicon and metagenome sequencing, combined with X-ray computed tomography, we investigated how water availability and substrate architecture modulated the taxonomic and functional composition of gypsum endolithic communities in the Atacama Desert, Chile. We found that communities inhabiting gypsum rocks with a more fragmented substrate architecture had higher taxonomic and functional diversity, despite having less water available. This effect was tightly linked with community connectedness and likely the result of niche differentiation. Gypsum communities were functionally similar, yet adapted to their unique micro-habitats by modulating their carbon and energy acquisition strategies and their growth modalities. Reconstructed population genomes showed that these endolithic microbial populations encoded potential pathways for anoxygenic phototrophy and atmospheric hydrogen oxidation as supplemental energy sources. This article is protected by copyright. All rights reserved.

RevDate: 2020-10-20

Sternes PR, Martin TM, Paley M, et al (2020)

HLA-A alleles including HLA-A29 affect the composition of the gut microbiome: a potential clue to the pathogenesis of birdshot retinochoroidopathy.

Scientific reports, 10(1):17636 pii:10.1038/s41598-020-74751-0.

Birdshot retinochoroidopathy occurs exclusively in individuals who are HLA-A29 positive. The mechanism to account for this association is unknown. The gut microbiome has been causally implicated in many immune-mediated diseases. We hypothesized that HLA-A29 would affect the composition of the gut microbiome, leading to a dysbiosis and immune-mediated eye disease. Fecal and intestinal biopsy samples were obtained from 107 healthy individuals from Portland, Oregon environs, 10 of whom were HLA-A29 positive, undergoing routine colonoscopy. Bacterial profiling was achieved via 16S rRNA metabarcoding. Publicly available whole meta-genome sequencing data from the Human Microbiome Project (HMP), consisting of 298 healthy controls mostly of US origin, were also interrogated. PERMANOVA and sparse partial least squares discriminant analysis (sPLSDA) demonstrated that subjects who were HLA-A29 positive differed in bacterial species composition (beta diversity) compared to HLA-A29 negative subjects in both the Portland (p = 0.019) and HMP cohorts (p = 0.0002). The Portland and HMP cohorts evidenced different subsets of bacterial species associated with HLA-A29 status, likely due to differences in the metagenomic techniques employed. The functional composition of the HMP cohort did not differ overall (p = 0.14) between HLA-A29 positive and negative subjects, although some distinct pathways such as heparan sulfate biosynthesis showed differences. As we and others have shown for various HLA alleles, the HLA allotype impacts the composition of the microbiome. We hypothesize that HLA-A29 may predispose chorioretinitis via an altered gut microbiome.

RevDate: 2020-10-20

Kim J, Cho Y, Seo MR, et al (2020)

Quantitative characterization of Clostridioides difficile population in the gut microbiome of patients with C. difficile infection and their association with clinical factors.

Scientific reports, 10(1):17608 pii:10.1038/s41598-020-74090-0.

Objective was to analyse bacterial composition and abundance of Clostridioides difficile in gut microbiome of patients with C. difficile infection (CDI) in association with clinical characteristics. Whole metagenome sequencing of gut microbiome of 26 CDI patients was performed, and the relative abundance of C. difficile and its toxin genes was measured. Clinical characteristics of the patients were obtained through medical records. A strong correlation between the abundance of C. difficile and tcdB genes in CDI patients was found. The relative abundance of C. difficile in the gut microbiome ranged from undetectable to 2.8% (median 0.089). Patients with fever exhibited low abundance of C. difficile in their gut, and patients with fewer C. difficile organisms required long-term anti-CDI treatment. Abundance of Bifidobacterium and Bacteroides negatively correlated with that of C. difficile at the genus level. CDI patients were clustered using the bacterial composition of the gut: one with high population of Enterococcus (cluster 1, n = 12) and another of Bacteroides or Lactobacillus (cluster 2, n = 14). Cluster1 showed significantly lower bacterial diversity and clinical cure at the end of treatment. Additionally, patients with CDI exhibited increased ARGs; notably, blaTEM, blaSHV and blaCTX-M were enriched. C. difficile existed in variable proportion of the gut microbiome in CDI patients. CDI patients with Enterococcus-rich microbiome in the gut had lower bacterial diversity and poorer clinical cure.

RevDate: 2020-10-20

Herold M, Martínez Arbas S, Narayanasamy S, et al (2020)

Integration of time-series meta-omics data reveals how microbial ecosystems respond to disturbance.

Nature communications, 11(1):5281 pii:10.1038/s41467-020-19006-2.

The development of reliable, mixed-culture biotechnological processes hinges on understanding how microbial ecosystems respond to disturbances. Here we reveal extensive phenotypic plasticity and niche complementarity in oleaginous microbial populations from a biological wastewater treatment plant. We perform meta-omics analyses (metagenomics, metatranscriptomics, metaproteomics and metabolomics) on in situ samples over 14 months at weekly intervals. Based on 1,364 de novo metagenome-assembled genomes, we uncover four distinct fundamental niche types. Throughout the time-series, we observe a major, transient shift in community structure, coinciding with substrate availability changes. Functional omics data reveals extensive variation in gene expression and substrate usage amongst community members. Ex situ bioreactor experiments confirm that responses occur within five hours of a pulse disturbance, demonstrating rapid adaptation by specific populations. Our results show that community resistance and resilience are a function of phenotypic plasticity and niche complementarity, and set the foundation for future ecological engineering efforts.

RevDate: 2020-10-20

Cissell EC, SJ McCoy (2020)

Shotgun metagenomic sequencing reveals the full taxonomic, trophic, and functional diversity of a coral reef benthic cyanobacterial mat from Bonaire, Caribbean Netherlands.

The Science of the total environment pii:S0048-9697(20)36248-3 [Epub ahead of print].

Anthropogenic forcing is spurring cyanobacterial proliferation in aquatic ecosystems worldwide. While planktonic cyanobacterial blooms have received substantial research attention, benthic blooms of mat-forming cyanobacteria have received considerably less attention, especially benthic mat blooms on coral reefs. Resultingly, numerous aspects of coral reef benthic cyanobacterial bloom ecology remain unknown, including underlying biodiversity in the mat communities. Most previous characterizations of coral reef cyanobacterial mat composition have only considered the cyanobacterial component. Without an unbiased characterization of full community diversity, we cannot predict whole-community response to anthropogenic inputs or effectively determine appropriate mitigation strategies. Here, we advocate for the implementation of shotgun sequencing techniques to study coral reef cyanobacterial mats worldwide, utilizing a case study of a coral reef benthic cyanobacterial mat sampled from the island of Bonaire, Caribbean Netherlands. Read-based taxonomic profiling revealed that Cyanobacteria was present at only 47.57% relative abundance in a coral reef cyanobacterial mat, with non-cyanobacterial members of the sampled mat community, including diatoms (0.78%), fungi (0.25%), Archaea (0.34%), viruses (0.08%), and other bacteria (45.78%), co-dominating the community. We found numerous gene families for regulatory systems and for functional pathways (both aerobic and anaerobic). These gene families were involved in community coordination; photosynthesis; nutrient scavenging; and the cycling of sulfur, nitrogen, phosphorous, and iron. We also report bacteriophage (including prophage) sequences associated with this subtidal coral reef cyanobacterial mat, which could contribute to intra-mat nutrient cycling and bloom dynamics. Overall, our results suggest that Cyanobacteria-focused analysis of coral reef cyanobacterial mats underestimates mat diversity and fails to capture community members possessing broad metabolic potential for intra-mat nutrient scavenging, recycling, and retention that likely contribute to the contemporary success of cyanobacterial mats on reefs. We advocate for increased collaboration between microbiologists and coral reef ecologists to unite insights from each discipline and improve efforts to understand mat ecology.

RevDate: 2020-10-20

Ariaeenejad S, Sheykh Abdollahzadeh Mamaghani A, Maleki M, et al (2020)

A novel high performance in-silico screened metagenome-derived alkali-thermostable endo-β-1,4-glucanase for lignocellulosic biomass hydrolysis in the harsh conditions.

BMC biotechnology, 20(1):56 pii:10.1186/s12896-020-00647-6.

BACKGROUND: Lignocellulosic biomass, is a great resource for the production of bio-energy and bio-based material since it is largely abundant, inexpensive and renewable. The requirement of new energy sources has led to a wide search for novel effective enzymes to improve the exploitation of lignocellulose, among which the importance of thermostable and halotolerant cellulase enzymes with high pH performance is significant.

RESULTS: The primary aim of this study was to discover a novel alkali-thermostable endo-β-1,4-glucanase from the sheep rumen metagenome. At first, the multi-step in-silico screening approach was utilized to find primary candidate enzymes with superior properties. Among the computationally selected candidates, PersiCel4 was found and subjected to cloning, expression, and purification followed by functional and structural characterization. The enzymes' kinetic parameters, including Vmax, Km, and specific activity, were calculated. The PersiCel4 demonstrated its optimum activity at pH 8.5 and a temperature of 85 °C and was able to retain more than 70% of its activity after 150 h of storage at 85 °C. Furthermore, this enzyme was able to maintain its catalytic activity in the presence of different concentrations of NaCl and several metal ions contains Mg2+, Mn2+, Cu2+, Fe2+ and Ca2+. Our results showed that treatment with MnCl2 could enhance the enzyme's activity by 78%. PersiCel4 was ultimately used for enzymatic hydrolysis of autoclave pretreated rice straw, the most abundant agricultural waste with rich cellulose content. In autoclave treated rice straw, enzymatic hydrolysis with the PersiCel4 increased the release of reducing sugar up to 260% after 72 h in the harsh condition (T = 85 °C, pH = 8.5).

CONCLUSION: Considering the urgent demand for stable cellulases that are operational on extreme temperature and pH conditions and due to several proposed distinctive characteristics of PersiCel4, it can be used in the harsh condition for bioconversion of lignocellulosic biomass.

RevDate: 2020-10-19

Chamakura KR, R Young (2020)

Single-gene lysis in the metagenomic era.

Current opinion in microbiology, 56:109-117 pii:S1369-5274(20)30119-3 [Epub ahead of print].

The small lytic phages (Microviridae and Leviviridae), effect bacterial lysis with the product of a single gene. The three well-studied single-gene lysis (Sgl) proteins (E of φX174, A2 of Qβ, and LysM of phage M) lack direct muralytic activity, and have been shown to function as 'protein antibiotics' by acting as noncompetitive inhibitors of conserved peptidoglycan (PG) biosynthesis enzymes, MurA, MraY, and MurJ respectively. The fourth, protein L of MS2, does not inhibit PG biosynthesis but instead is hypothesized to trigger host autolytic response through an unknown mechanism. Recent advances in meta-omics approaches have led to an explosion in the available genomes of small lytic phages. Of the thousands of new genomes, only one annotated Sgl shared some sequence similarity with a known Sgl (L of MS2), highlighting the diversity in Sgls. The newly available genomic space serves as an untapped resource for discovering novel Sgls.

RevDate: 2020-10-19

Li YH, Huang YF, Chen TH, et al (2020)

Comparison of gut microbiota of healthy and diseased walking sticks, Phasmotaenia lanyuhensis.

Archives of insect biochemistry and physiology [Epub ahead of print].

Research on gut microbiota of phytophagous insects has shown to be important for the physiological functions of insect hosts; however, little is known about the changes in gut microbiota when they are suffering from environmental stress or pathogen infections. During rearing of Phasmotaenia lanyuhensis (Phasmatodea: Phasmatidae), sluggish locomotion was usually followed by the death of the insect with a symptom of melanization in the front part of the abdomen. Therefore, the abnormal individuals were initially classified into moribund, light- and serious-symptom based on the level of abnormal physiological circumstances and melanization. The gut microbiota of these samples were further investigated by 16S metagenomic sequencing and the differences in bacterial abundance and structure of bacterial community were analyzed. A decrease in microbiota diversity was observed in the diseased P. lanyuhensis, with the abundance of phyla Proteobacteria and Firmicute relatively higher compared to those without symptom. Interestingly, principal component analysis based on the bacterial richness was correlated to the level of melanization symptom in the diseased P. lanyuhensis, suggested the change in bacterial microbiota involved in this abnormal circumstance. However, the factor that caused the initial alternation of microbiota remains to be identified. Additionally, the lack of bacterial diversity (i.e., absence of Meiothermus and Nubsella spp.) in P. lanyuhensis might reduce the fitness for surviving. This report provided the comprehensive microbiota analysis for P. lanyuhensis and concluded that either the relative abundance or the bacterial diversity of microbiota in the insect digestive system may influence the physiological functions of phytophagous insects.

RevDate: 2020-10-19

Lai S, Jia L, Subramanian B, et al (2020)

mMGE: a database for human metagenomic extrachromosomal mobile genetic elements.

Nucleic acids research pii:5930394 [Epub ahead of print].

Extrachromosomal mobile genetic elements (eMGEs), including phages and plasmids, that can move across different microbes, play important roles in genome evolution and shaping the structure of microbial communities. However, we still know very little about eMGEs, especially their abundances, distributions and putative functions in microbiomes. Thus, a comprehensive description of eMGEs is of great utility. Here we present mMGE, a comprehensive catalog of 517 251 non-redundant eMGEs, including 92 492 plasmids and 424 759 phages, derived from diverse body sites of 66 425 human metagenomic samples. About half the eMGEs could be further grouped into 70 074 clusters using relaxed criteria (referred as to eMGE clusters below). We provide extensive annotations of the identified eMGEs including sequence characteristics, taxonomy affiliation, gene contents and their prokaryotic hosts. We also calculate the prevalence, both within and across samples for each eMGE and eMGE cluster, enabling users to see putative associations of eMGEs with human phenotypes or their distribution preferences. All eMGE records can be browsed or queried in multiple ways, such as eMGE clusters, metagenomic samples and associated hosts. The mMGE is equipped with a user-friendly interface and a BLAST server, facilitating easy access/queries to all its contents easily. mMGE is freely available for academic use at: https://mgedb.comp-sysbio.org.

RevDate: 2020-10-19

Marizzoni M, Cattaneo A, Mirabelli P, et al (2020)

Short-Chain Fatty Acids and Lipopolysaccharide as Mediators Between Gut Dysbiosis and Amyloid Pathology in Alzheimer's Disease.

Journal of Alzheimer's disease : JAD pii:JAD200306 [Epub ahead of print].

BACKGROUND: Metagenomic data support an association between certain bacterial strains and Alzheimer's disease (AD), but their functional dynamics remain elusive.

OBJECTIVE: To investigate the association between amyloid pathology, bacterial products such as lipopolysaccharide (LPS) and short chain fatty acids (SCFAs: acetate, valerate, butyrate), inflammatory mediators, and markers of endothelial dysfunction in AD.

METHODS: Eighty-nine older persons with cognitive performance from normal to dementia underwent florbetapir amyloid PET and blood collection. Brain amyloidosis was measured with standardized uptake value ratio versus cerebellum. Blood levels of LPS was measured by ELISA, SCFAs by mass spectrometry, cytokines by using real-time PCR, and biomarkers of endothelial dysfunction by flow cytometry. We investigated the association between the variables listed above with Spearman's rank test.

RESULTS: Amyloid SUVR uptake was positively associated with blood LPS (rho≥0.32, p≤0.006), acetate and valerate (rho≥0.45, p < 0.001), pro-inflammatory cytokines (rho≥0.25, p≤0.012), and biomarkers of endothelial dysfunction (rho≥0.25, p≤0.042). In contrast, it was negatively correlated with butyrate (rho≤-0.42, p≤0.020) and the anti-inflammatory cytokine IL10 (rho≤-0.26, p≤0.009). Endothelial dysfunction was positively associated with pro-inflammatory cytokines, acetate and valerate (rho≥0.25, p≤0.045) and negatively with butyrate and IL10 levels (rho≤-0.25, p≤0.038).

CONCLUSION: We report a novel association between gut microbiota-related products and systemic inflammation with brain amyloidosis via endothelial dysfunction, suggesting that SCFAs and LPS represent candidate pathophysiologic links between the gut microbiota and AD pathology.

RevDate: 2020-10-20

Mobegi FM, Leong LE, Thompson F, et al (2020)

Intestinal microbiology shapes population health impacts of diet and lifestyle risk exposures in Torres Strait Islander communities.

eLife, 9: pii:58407.

Poor diet and lifestyle exposures are implicated in substantial global increases in non-communicable disease burden in low-income, remote, and Indigenous communities. This observational study investigated the contribution of the fecal microbiome to influence host physiology in two Indigenous communities in the Torres Strait Islands: Mer, a remote island where a traditional diet predominates, and Waiben a more accessible island with greater access to takeaway food and alcohol. Counterintuitively, disease markers were more pronounced in Mer residents. However, island-specific differences in disease risk were explained, in part, by microbiome traits. The absence of Alistipes onderdonkii, for example, significantly (p=0.014) moderated island-specific patterns of systolic blood pressure in multivariate-adjusted models. We also report mediatory relationships between traits of the fecal metagenome, disease markers, and risk exposures. Understanding how intestinal microbiome traits influence response to disease risk exposures is critical for the development of strategies that mitigate the growing burden of cardiometabolic disease in these communities.

RevDate: 2020-10-20
CmpDate: 2020-10-20

Guo W, Xin M, Wang Z, et al (2020)

Origin and adaptation to high altitude of Tibetan semi-wild wheat.

Nature communications, 11(1):5085.

Tibetan wheat is grown under environmental constraints at high-altitude conditions, but its underlying adaptation mechanism remains unknown. Here, we present a draft genome sequence of a Tibetan semi-wild wheat (Triticum aestivum ssp. tibetanum Shao) accession Zang1817 and re-sequence 245 wheat accessions, including world-wide wheat landraces, cultivars as well as Tibetan landraces. We demonstrate that high-altitude environments can trigger extensive reshaping of wheat genomes, and also uncover that Tibetan wheat accessions accumulate high-altitude adapted haplotypes of related genes in response to harsh environmental constraints. Moreover, we find that Tibetan semi-wild wheat is a feral form of Tibetan landrace, and identify two associated loci, including a 0.8-Mb deletion region containing Brt1/2 homologs and a genomic region with TaQ-5A gene, responsible for rachis brittleness during the de-domestication episode. Our study provides confident evidence to support the hypothesis that Tibetan semi-wild wheat is de-domesticated from local landraces, in response to high-altitude extremes.

RevDate: 2020-10-20
CmpDate: 2020-10-20

Joseph J, S Chaurasia (2020)


Cornea, 39(11):26.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Mérot C, Oomen RA, Tigano A, et al (2020)

A Roadmap for Understanding the Evolutionary Significance of Structural Genomic Variation.

Trends in ecology & evolution, 35(7):561-572.

Structural genomic variants (SVs) are ubiquitous and play a major role in adaptation and speciation. Yet, comparative and population genomics have focused predominantly on gene duplications and large-effect inversions. The lack of a common framework for studying all SVs is hampering progress towards a more systematic assessment of their evolutionary significance. Here we (i) review how different types of SVs affect ecological and evolutionary processes; (ii) suggest unifying definitions and recommendations for future studies; and (iii) provide a roadmap for the integration of SVs in ecoevolutionary studies. In doing so, we lay the foundation for population genomics, theoretical, and experimental approaches to understand how the full spectrum of SVs impacts ecological and evolutionary processes.

RevDate: 2020-10-20
CmpDate: 2020-10-20

Bittinger K, Zhao C, Li Y, et al (2020)

Bacterial colonization reprograms the neonatal gut metabolome.

Nature microbiology, 5(6):838-847.

Initial microbial colonization and later succession in the gut of human infants are linked to health and disease later in life. The timing of the appearance of the first gut microbiome, and the consequences for the early life metabolome, are just starting to be defined. Here, we evaluated the gut microbiome, proteome and metabolome in 88 African-American newborns using faecal samples collected in the first few days of life. Gut bacteria became detectable using molecular methods by 16 h after birth. Detailed analysis of the three most common species, Escherichia coli, Enterococcus faecalis and Bacteroides vulgatus, did not suggest a genomic signature for neonatal gut colonization. The appearance of bacteria was associated with reduced abundance of approximately 50 human proteins, decreased levels of free amino acids and an increase in products of bacterial fermentation, including acetate and succinate. Using flux balance modelling and in vitro experiments, we provide evidence that fermentation of amino acids provides a mechanism for the initial growth of E. coli, the most common early colonizer, under anaerobic conditions. These results provide a deep characterization of the first microbes in the human gut and show how the biochemical environment is altered by their appearance.

RevDate: 2020-10-20
CmpDate: 2020-10-20

Casals-Pascual C, González A, Vázquez-Baeza Y, et al (2020)

Microbial Diversity in Clinical Microbiome Studies: Sample Size and Statistical Power Considerations.

Gastroenterology, 158(6):1524-1528.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Lin B (2020)

China and Multiomics Research and Development Ecosystem: A Horizon Scanning and Current State of the Art.

Omics : a journal of integrative biology, 24(1):3-4.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Bartolomaeus TUP, SK Forslund (2020)

Hitchhiker's guide to microbiome studies.

Cardiovascular research, 116(3):e44-e47.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Li X, Cao Z, Yang Y, et al (2019)

Correlation between Jejunal Microbial Diversity and Muscle Fatty Acids Deposition in Broilers Reared at Different Ambient Temperatures.

Scientific reports, 9(1):11022 pii:10.1038/s41598-019-47323-0.

Temperature, which is an important environmental factor in broiler farming, can significantly influence the deposition of fatty acids in muscle. 300 one-day-old broiler chicks were randomly divided into three groups and reared at high, medium and low temperatures (HJ, MJ and LJ), respectively. Breast muscle and jejunal chyme samples were collected and subjected to analyses of fatty acid composition and 16S rRNA gene sequencing. Through spearman's rank correlation coefficient, the data were used to characterize the correlation between jejunal microbial diversity and muscle fatty acid deposition in the broilers. The results showed that Achromobacter, Stenotrophomonas, Pandoraea, Brevundimonas, Petrobacter and Variovorax were significantly enriched in the MJ group, and all of them were positively correlated with the fatty acid profiling of muscle and multiple lipid metabolism signaling pathways. Lactobacillus was significantly enriched in the HJ group and exhibited a positive correlation with fatty acid deposition. Pyramidobacter, Dialister, Bacteroides and Selenomonas were significantly enriched in the LJ group and displayed negative correlation with fatty acid deposition. Taken together, this study demonstrated that the jejunal microflora manifested considerable changes at high and low ambient temperatures and that jejunal microbiota changes were correlated with fatty acid deposition of muscle in broilers.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Bang S, Yoo D, Kim SJ, et al (2019)

Establishment and evaluation of prediction model for multiple disease classification based on gut microbial data.

Scientific reports, 9(1):10189 pii:10.1038/s41598-019-46249-x.

Diseases prediction has been performed by machine learning approaches with various biological data. One of the representative data is the gut microbial community, which interacts with the host's immune system. The abundance of a few microorganisms has been used as markers to predict diverse diseases. In this study, we hypothesized that multi-classification using machine learning approach could distinguish the gut microbiome from following six diseases: multiple sclerosis, juvenile idiopathic arthritis, myalgic encephalomyelitis/chronic fatigue syndrome, acquired immune deficiency syndrome, stroke and colorectal cancer. We used the abundance of microorganisms at five taxonomy levels as features in 696 samples collected from different studies to establish the best prediction model. We built classification models based on four multi-class classifiers and two feature selection methods including a forward selection and a backward elimination. As a result, we found that the performance of classification is improved as we use the lower taxonomy levels of features; the highest performance was observed at the genus level. Among four classifiers, LogitBoost-based prediction model outperformed other classifiers. Also, we suggested the optimal feature subsets at the genus-level obtained by backward elimination. We believe the selected feature subsets could be used as markers to distinguish various diseases simultaneously. The finding in this study suggests the potential use of selected features for the diagnosis of several diseases.

RevDate: 2020-10-20
CmpDate: 2020-10-20

Di Salvo M, Calcagnile M, Talà A, et al (2019)

The Microbiome of the Maculinea-Myrmica Host-Parasite Interaction.

Scientific reports, 9(1):8048 pii:10.1038/s41598-019-44514-7.

Maculinea (=Phengaris) are endangered butterflies that are characterized by a very complex biological cycle. Maculinea larvae behave as obligate parasites whose survival is strictly dependent on both particular food plants and species-specific Myrmica ants. In this interaction, Maculinea caterpillars induce Myrmica workers to retrieve and rear them in the nest by chemical and acoustic deception. Social insect symbiotic microorganisms play a key role in intraspecific and interspecific communication; therefore, it is possible that the Maculinea caterpillar microbiome might be involved in the chemical cross-talk by producing deceptive semiochemicals for host ants. To address this point, the microbiota of Maculinea alcon at different larval stages (phytophagous early larvae, intermediate larvae, carnivorous late larvae) was analyzed by using 16S rRNA-guided metabarcoding approach and compared to that of the host ant Myrmica scabrinodis. Structural and deduced functional profiles of the microbial communities were recorded, which were used to identify specific groups of microorganisms that may be involved in the chemical cross-talk. One of the most notable features was the presence in all larval stages and in the ants of two bacteria, Serratia marcescens and S. entomophila, which are involved in the chemical cross-talk between the microbes and their hosts.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Golberg A, Liberzon A, Vitkin E, et al (2020)

Design and Analysis of Offshore Macroalgae Biorefineries.

Methods in molecular biology (Clifton, N.J.), 1980:9-33.

Displacing fossil fuels and their derivatives with renewables, and increasing sustainable food production are among the major challenges facing the world in the coming decades. A possible, sustainable direction for addressing this challenge is the production of biomass and the conversion of this biomass to the required products through a complex system coined biorefinery. Terrestrial biomass and microalgae are possible sources; however, concerns over net energy balance, potable water use, environmental hazards, and uncertainty in the processing technologies raise questions regarding their actual potential to meet the anticipated food, feed, and energy challenges in a sustainable way. Alternative sustainable sources for biorefineries are macroalgae grown and processed offshore. However, implementation of the offshore biorefineries requires detailed analysis of their technological, economic, and environmental performance. In this chapter, the basic principles of marine biorefineries design are shown. The methods to integrate thermodynamic efficiency, investment, and environmental aspects are discussed. The performance improvement by development of new cultivation methods that fit macroalgae physiology and development of new fermentation methods that address macroalgae unique chemical composition is shown.

RevDate: 2020-10-19

Valdes L, Bispo P, L Sobrin (2020)

Application of Metagenomic Sequencing in the Diagnosis of Infectious Uveitis.

Seminars in ophthalmology [Epub ahead of print].

Purpose: to summarize the origin and very recent history of the use of metagenomic sequencing for the diagnosis of infectious uveitis, convey the technique as described by one of the primary institutions experimenting with the technology, and present recent successful applications of the technology as well as potential advantages and pitfalls compared to other current diagnostic tools.Methods: review of peer-reviewed literature concerning metagenomic sequencing for the diagnosis of infectious uveitis.Conclusion: compared to existing diagnostic methods, metagenomic deep sequencing is a sensitive, unbiased, and comprehensive technique with great potential for diagnosing the causative pathogens of cases of infectious uveitis. However, many issues remain to be addressed in the process of developing this technology, including but not limited to the potentially overwhelming amount of information generated, definition of diagnostic thresholds, demonstration of validity, contamination, and cost.

RevDate: 2020-10-19

Abd El-Aziz NK, Gharib AA, Mohamed EAA, et al (2020)

Real-time PCR versus MALDI-TOF MS and culture-based techniques for diagnosis of bloodstream and pyogenic infections in humans and animals.

Journal of applied microbiology [Epub ahead of print].

AIMS: This study was applied to evaluate the usefulness of a high-throughput sample preparation protocol prior to the application of quantitative real-time PCR (qPCR) for the early diagnosis of bloodstream and pyogenic infections in humans and animals compared to matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and classical culture.

METHODS AND RESULTS: Saponin-mediated selective host cell lysis combined with DNase-1 was applied for processing of whole blood and pus clinical samples collected from suspected cases of septicaemia and pyogenic infections in humans and animals. The pre-PCR processing strategy enabled the recovery of microbial cells with no changes in their colony forming units immediately after the addition of saponin. DNase-1 was efficient for removing the DNAs from the host cells as well as dead cells with damaged cell membranes. The metagenomic qPCR and MALDI-TOF MS could identify the bacterial community of sepsis at species level with a concordance of 97·37% unlike the conventional culture. According to qPCR results, Staphylococcus aureus (24·24%) was predominated in animal pyogenic infections, whereas Klebsiella pneumonia (31·81%) was commonly detected in neonatal sepsis.

CONCLUSIONS: Saponin combined with DNase-1 allowed the efficient recovery of microbial DNA from blood and pus samples in sepsis using qPCR assay.

Metagenomic qPCR could identify a broad range of bacteria directly from blood and pus with more sensitivity, higher discriminatory power and shorter turnaround time than those using MALDI-TOF MS and conventional culture. This might allow a timely administration of a prompt treatment.

RevDate: 2020-10-19

Flores Bueso Y, Walker SP, M Tangney (2020)

Characterization of FFPE-induced bacterial DNA damage and development of a repair method.

Biology methods & protocols, 5(1):bpaa015 pii:bpaa015.

Formalin-fixed, paraffin-embedded (FFPE) specimens have huge potential as source material in the field of human microbiome research. However, the effects of FFPE processing on bacterial DNA remain uncharacterized. Any effects are relevant for microbiome studies, where DNA template is often minimal and sequences studied are not limited to one genome. As such, we aimed to both characterize this FFPE-induced bacterial DNA damage and develop strategies to reduce and repair this damage. Our analyses indicate that bacterial FFPE DNA is highly fragmented, a poor template for PCR, crosslinked and bears sequence artefacts derived predominantly from oxidative DNA damage. Two strategies to reduce this damage were devised - an optimized decrosslinking procedure reducing sequence artefacts generated by high-temperature incubation, and secondly, an in vitro reconstitution of the base excision repair pathway. As evidenced by whole genome sequencing, treatment with these strategies significantly increased fragment length, reduced the appearance of sequence artefacts and improved the sequencing readability of bacterial and mammalian FFPE DNA. This study provides a new understanding of the condition of bacterial DNA in FFPE specimens and how this impacts downstream analyses, in addition to a strategy to improve the sequencing quality of bacterial and possibly mammalian FFPE DNA.

RevDate: 2020-10-19

Rupert R, Lie GJCW, John DV, et al (2020)

Metagenomic data of bacterial community from different land uses at the river basin, Kelantan.

Data in brief, 33:106351 pii:S2352-3409(20)31244-0.

The data provided in the article includes the sequence of bacterial 16S rRNA gene from a high conservation value forest, logged forest, rubber plantation and oil palm plantation collected at Kelantan river basin. The logged forest area was previously notified as a flooding region. The total gDNA of bacterial community was amplified via polymerase chain reaction at V3-V4 regions using a pair of specific universal primer. Amplicons were sequenced on Illumina HiSeq paired-end platform to generate 250 bp paired-end raw reads. Several bioinformatics tools such as FLASH, QIIME and UPARSE were used to process the reads generated for OTU analysis. Meanwhile, R&D software was used to construct the taxonomy tree for all samples. Raw data files are available at the Sequence Read Archive (SRA), NCBI and data information can be found at the BioProject and BioSample, NCBI. The data shows the comparison of bacterial community between the natural forest and different land uses.

RevDate: 2020-10-19

Wirth R, Pap B, Böjti T, et al (2020)

Chlorella vulgaris and Its Phycosphere in Wastewater: Microalgae-Bacteria Interactions During Nutrient Removal.

Frontiers in bioengineering and biotechnology, 8:557572.

Microalgae-based bioenergy production is a promising field with regard to the wide variety of algal species and metabolic potential. The use of liquid wastes as nutrient clearly improves the sustainability of microalgal biofuel production. Microalgae and bacteria have an ecological inter-kingdom relationship. This microenvironment called phycosphere has a major role in the ecosystem productivity and can be utilized both in bioremediation and biomass production. However, knowledge on the effects of indigenous bacteria on microalgal growth and the characteristics of bacterial communities associated with microalgae are limited. In this study municipal, industrial and agricultural liquid waste derivatives were used as cultivation media. Chlorella vulgaris green microalgae and its bacterial partners efficiently metabolized the carbon, nitrogen and phosphorous content available in these wastes. The read-based metagenomics approach revealed a diverse microbial composition at the start point of cultivations in the different types of liquid wastes. The relative abundance of the observed taxa significantly changed over the cultivation period. The genome-centric reconstruction of phycospheric bacteria further explained the observed correlations between the taxonomic composition and biomass yield of the various waste-based biodegradation systems. Functional profile investigation of the reconstructed microbes revealed a variety of relevant biological processes like organic acid oxidation and vitamin B synthesis. Thus, liquid wastes were shown to serve as valuable resources of nutrients as well as of growth promoting bacteria enabling increased microalgal biomass production.

RevDate: 2020-10-19

Kumar A, Malla MA, A Dubey (2020)

With Corona Outbreak: Nature Started Hitting the Reset Button Globally.

Frontiers in public health, 8:569353.

Considering the potential threat and the contagious nature of the Covid-19 pandemic, lockdowns have been implemented worldwide to stop the spread of this novel virus. The coronavirus pandemic has hit the world severely, representing the most severe threat to human health in more than a century. The environment from local to global scales has witnessed apparent positive and negative impacts. Global lockdowns have drastically altered the patterns of energy demand and have caused an economic downturn but at the same time, have provided an upside-cleaner global environment. Such immense unintended advantages offer opportunities for unprecedented insights into the dynamics of our natural and built environments that can lead to viable paths for the conservation and perpetuation of the recovered environments and through sensible policies and practices that can help to create new recovery pathways. Knowledge gained from the studies suggests that a substantial relationship exists between the contingency measures and environmental health. Here in this review, the authors discussed the impact of coronavirus pandemic on human life, healthcare organizations, and the environment. The parallels between the Covid-19 and other diseases are mentioned. Finally, the impact of Covid-19 on society and the global environment has also been highlighted.

RevDate: 2020-10-19

Chen J, Hilt EE, Li F, et al (2020)

Epidemiological and Genomic Analysis of SARS-CoV-2 in 10 Patients From a Mid-Sized City Outside of Hubei, China in the Early Phase of the COVID-19 Outbreak.

Frontiers in public health, 8:567621.

A novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing Coronavirus Disease 2019 (COVID-19) pandemic. In this study, we performed a comprehensive epidemiological and genomic analysis of SARS-CoV-2 genomes from 10 patients in Shaoxing (Zhejiang Province), a mid-sized city outside of the epicenter Hubei province, China, during the early stage of the outbreak (late January to early February, 2020). We obtained viral genomes with >99% coverage and a mean depth of 296X demonstrating that viral genomic analysis is feasible via metagenomics sequencing directly on nasopharyngeal samples with SARS-CoV-2 Real-time PCR Ct values <28. We found that a cluster of four patients with travel history to Hubei shared the exact same virus with patients from Wuhan, Taiwan, Belgium, and Australia, highlighting how quickly this virus spread to the globe. The virus from another cluster of two family members living together without travel history but with a sick contact of a confirmed case from another city outside of Hubei accumulated significantly more mutations (9 SNPs vs. average 4 SNPs), suggesting a complex and dynamic nature of this outbreak. Our findings add to the growing knowledge of the epidemiological and genomic characteristics of SARS-CoV-2 and offers a glimpse into the early phase of this viral infection outside of Hubei, China.

RevDate: 2020-10-19

Manenzhe RI, Dube FS, Wright M, et al (2020)

Characterization of Pneumococcal Colonization Dynamics and Antimicrobial Resistance Using Shotgun Metagenomic Sequencing in Intensively Sampled South African Infants.

Frontiers in public health, 8:543898.

Background: There remains a significant proportion of deaths due to pneumococcal pneumonia in infants from low- and middle-income countries despite the marginal global declines recorded in the past decade. Monitoring changes in pneumococcal carriage is key to understanding vaccination-induced shifts in the ecology of carriage, patterns of antimicrobial resistance, and impact on health. We longitudinally investigated pneumococcal carriage dynamics in PCV-13 vaccinated infants by collecting nasopharyngeal (NP) samples at 2-weekly intervals from birth through the first year of life from 137 infants. As a proof of concept, 196 NP samples were retrieved from a subset of 23 infants to explore strain-level pneumococcal colonization patterns and associated antimicrobial-resistance determinants. These were selected on the basis of changes in serotype and antibiogram over time. NP samples underwent short-term enrichment for streptococci prior to total nucleic acid extraction and whole metagenome shotgun sequencing (WMGS). Reads were assembled and aligned to pneumococcal reference genomes for the extraction of pneumococcal and non-pneumococcal bacterial reads. Pneumococcal contigs were aligned to the Antibiotic Resistance Gene-ANNOTation database of acquired AMR genes. In silico pneumococcal capsular and multilocus sequence typing were performed. Results: Of the 196 samples sequenced, 174 had corresponding positive cultures for pneumococci, of which, 152 were assigned an in silico serotype. Metagenomic sequencing detected a single pneumococcal serotype in 85% (129/152), and co-colonization in 15% (23/152) of the samples. Twenty-two different pneumococcal serotypes were identified, with 15B/15C and 16F being the most common non-PCV13 serotypes, while 23F and 19A were the most common PCV13 serotypes. Twenty-six different sequence types (STs), including four novel STs were identified in silico. Mutations in the folA and folP genes, associated with cotrimoxazole resistance, were detected in 89% (87/98) of cotrimoxazole-non-susceptible pneumococci, as well as in the pbp1a and pbp2x genes, in penicillin non-susceptible ST705215B/15C isolates. Conclusions: Metagenomic sequencing of NP samples is a valuable culture-independent technique for a detailed evaluation of the pneumococcal component and resistome of the NP microbiome. This method allowed for the detection of novel STs, as well as co-colonization, with a predominance of non-PCV13 serotypes in this cohort. Forty-eight resistance genes, as well as mutations associated with resistance were detected, but the correlation with phenotypic non-susceptibility was lower than expected.

RevDate: 2020-10-19

Chen H, Fan C, Gao H, et al (2020)

Leishmaniasis Diagnosis via Metagenomic Next-Generation Sequencing.

Frontiers in cellular and infection microbiology, 10:528884.

Leishmaniasis is a vector-borne disease caused by Leishmania. Although the incidence of leishmaniasis in China is currently low, it has not been completely eradicated. In 2019, visceral leishmaniasis was diagnosed in three patients using bone marrow microscopic examination and metagenomic next-generation sequencing (mNGS). The bone marrow mNGS results from the three patients indicated that 99.9, 99.6, and 30.3% of non-human reads matched the Leishmania genome, and plasma mNGS results from one of the patients revealed that 46.2% of non-human reads matched the Leishmania genome. In the second patient's plasma, no Leishmania sequences were detected by plasma mNGS, and the third patient's plasma was unavailable. The pathogen in all three patients was identified as Leishmania infantum. Leishmania amastigotes were observed by microscopic examination of bone marrow smears in all three patients, but were not found in peripheral blood smears. This indicates that the sensitivity of mNGS is higher than that of smear microscopy and that mNGS can be used to identify Leishmania at the species level. All three patients were elderly male farmers, two from Shanxi and one from Beijing. All three patients had splenomegaly and pancytopenia. Originally, these patients were misdiagnosed and treated for extended periods in other hospitals. Diagnoses of visceral leishmaniasis took place 6, 2, and 2 months after the onset of symptoms in the three patients. In conclusion, this study confirms that bone marrow mNGS can be used to quickly and accurately confirm a diagnosis in patients with suspected leishmaniasis.

RevDate: 2020-10-19

Capo E, Bravo AG, Soerensen AL, et al (2020)

Deltaproteobacteria and Spirochaetes-Like Bacteria Are Abundant Putative Mercury Methylators in Oxygen-Deficient Water and Marine Particles in the Baltic Sea.

Frontiers in microbiology, 11:574080.

Methylmercury (MeHg), a neurotoxic compound biomagnifying in aquatic food webs, can be a threat to human health via fish consumption. However, the composition and distribution of the microbial communities mediating the methylation of mercury (Hg) to MeHg in marine systems remain largely unknown. In order to fill this knowledge gap, we used the Baltic Sea Reference Metagenome (BARM) dataset to study the abundance and distribution of the genes involved in Hg methylation (the hgcAB gene cluster). We determined the relative abundance of the hgcAB genes and their taxonomic identity in 81 brackish metagenomes that cover spatial, seasonal and redox variability in the Baltic Sea water column. The hgcAB genes were predominantly detected in anoxic water, but some hgcAB genes were also detected in hypoxic and normoxic waters. Phylogenetic analysis identified putative Hg methylators within Deltaproteobacteria, in oxygen-deficient water layers, but also Spirochaetes-like and Kiritimatiellaeota-like bacteria. Higher relative quantities of hgcAB genes were found in metagenomes from marine particles compared to free-living communities in anoxic water, suggesting that such particles are hotspot habitats for Hg methylators in oxygen-depleted seawater. Altogether, our work unveils the diversity of the microorganisms with the potential to mediate MeHg production in the Baltic Sea and pinpoint the important ecological niches for these microorganisms within the marine water column.

RevDate: 2020-10-19

Khadempour L, Fan H, Keefover-Ring K, et al (2020)

Metagenomics Reveals Diet-Specific Specialization of Bacterial Communities in Fungus Gardens of Grass- and Dicot-Cutter Ants.

Frontiers in microbiology, 11:570770.

Leaf-cutter ants in the genus Atta are dominant herbivores in the Neotropics. While most species of Atta cut dicots to incorporate into their fungus gardens, some species specialize on grasses. Here we examine the bacterial community associated with the fungus gardens of grass- and dicot-cutter ants to examine how changes in substrate input affect the bacterial community. We sequenced the metagenomes of 12 Atta fungus gardens, across four species of ants, with a total of 5.316 Gbp of sequence data. We show significant differences in the fungus garden bacterial community composition between dicot- and grass-cutter ants, with grass-cutter ants having lower diversity. Reflecting this difference in community composition, the bacterial functional profiles between the fungus gardens are significantly different. Specifically, grass-cutter ant fungus garden metagenomes are particularly enriched for genes responsible for amino acid, siderophore, and terpenoid biosynthesis while dicot-cutter ant fungus gardens metagenomes are enriched in genes involved in membrane transport. Differences between community composition and functional capacity of the bacteria in the two types of fungus gardens reflect differences in the substrates that the ants incorporated. These results show that different substrate inputs matter for fungus garden bacteria and shed light on the potential role of bacteria in mediating the ants' transition to the use of a novel substrate.

RevDate: 2020-10-19

Hidalgo KJ, Sierra-Garcia IN, Dellagnezze BM, et al (2020)

Metagenomic Insights Into the Mechanisms for Biodegradation of Polycyclic Aromatic Hydrocarbons in the Oil Supply Chain.

Frontiers in microbiology, 11:561506.

Petroleum is a very complex and diverse organic mixture. Its composition depends on reservoir location and in situ conditions and changes once crude oil is spilled into the environment, making the characteristics associated with every spill unique. Polycyclic aromatic hydrocarbons (PAHs) are common components of the crude oil and constitute a group of persistent organic pollutants. Due to their highly hydrophobic, and their low solubility tend to accumulate in soil and sediment. The process by which oil is sourced and made available for use is referred to as the oil supply chain and involves three parts: (1) upstream, (2) midstream and (3) downstream activities. As consequence from oil supply chain activities, crude oils are subjected to biodeterioration, acidification and souring, and oil spills are frequently reported affecting not only the environment, but also the economy and human resources. Different bioremediation techniques based on microbial metabolism, such as natural attenuation, bioaugmentation, biostimulation are promising approaches to minimize the environmental impact of oil spills. The rate and efficiency of this process depend on multiple factors, like pH, oxygen content, temperature, availability and concentration of the pollutants and diversity and structure of the microbial community present in the affected (contaminated) area. Emerging approaches, such as (meta-)taxonomics and (meta-)genomics bring new insights into the molecular mechanisms of PAH microbial degradation at both single species and community levels in oil reservoirs and groundwater/seawater spills. We have scrutinized the microbiological aspects of biodegradation of PAHs naturally occurring in oil upstream activities (exploration and production), and crude oil and/or by-products spills in midstream (transport and storage) and downstream (refining and distribution) activities. This work addresses PAH biodegradation in different stages of oil supply chain affecting diverse environments (groundwater, seawater, oil reservoir) focusing on genes and pathways as well as key players involved in this process. In depth understanding of the biodegradation process will provide/improve knowledge for optimizing and monitoring bioremediation in oil spills cases and/or to impair the degradation in reservoirs avoiding deterioration of crude oil quality.

RevDate: 2020-10-19

Zhan M, Wang L, Xie C, et al (2020)

Succession of Gut Microbial Structure in Twin Giant Pandas During the Dietary Change Stage and Its Role in Polysaccharide Metabolism.

Frontiers in microbiology, 11:551038.

Adaptation to a bamboo diet is an essential process for giant panda growth, and gut microbes play an important role in the digestion of the polysaccharides in bamboo. The dietary transition in giant panda cubs is particularly complex, but it is an ideal period in which to study the effects of gut microbes on polysaccharide use because their main food changes from milk to bamboo (together with some bamboo shoot and coarse pastry). Here, we used 16S rDNA and internal transcribed spacer 1 (ITS1) DNA sequencing and metagenomic sequencing analysis to investigate the succession of the gut microbial structure in feces sampled from twin giant panda cubs during the completely dietary transition and determine the abundances of polysaccharide-metabolizing genes and their corresponding microbes to better understand the degradation of bamboo polysaccharides. Successive changes in the gut microbial diversity and structure were apparent in the growth of pandas during dietary shift process. Microbial diversity increased after the introduction of supplementary foods and then varied in a complex way for 1.5-2 years as bamboo and complex food components were introduced. They then stabilized after 2 years, when the cubs consumed a specialized bamboo diet. The microbes had more potential to metabolize the cellulose in bamboo than the hemicellulose, providing genes encoding cellulase systems corresponding to glycoside hydrolases (GHs; such as GH1, GH3, GH5, GH8, GH9, GH74, and GH94). The cellulose-metabolizing species (or genes) of gut bacteria was more abundant than that of gut fungi. Although cellulose-metabolizing species did not predominate in the gut bacterial community, microbial interactions allowed the giant pandas to achieve the necessary dietary shift and ultimately adapt to a bamboo diet.

RevDate: 2020-10-19

Bajaj JS, Acharya C, Sikaroodi M, et al (2020)

Cost-effectiveness of integrating gut microbiota analysis into hospitalisation prediction in cirrhosis.

GastroHep, 2(2):79-86.

Background: Admissions in cirrhosis are expensive and often unpredictable based on purely clinical variables. Admissions could be related to complications associated with gut microbial changes, which can improve prognostication. However, the cost-effectiveness is unclear.

Aims: Determine cost-effectiveness of adding gut microbiota analysis to clinical parameters in prediction and subsequent reduction of admissions in cirrhosis.

Methods: Using a Markov model of 1000 cirrhosis patients over 90 days, we modeled microbiota testing using 16srRNA ($250/sample), low-depth ($350/sample) and high-depth ($650/sample) metagenomics added to standard-of-care (SOC) for prevention of admissions using standard outcome costs and rates of development. We generated quality of life years (QALY) and Incremental cost-effectiveness ratios (ICER) for the base scenarios and performed sensitivity analyses by varying costs for outcomes (transplant, death, admission) and admission rates (40%, range 25%-60%).

Results: Using fixed costs of outcomes and outcome rates, microbiota analysis was cost-saving ($47K-$97K) at $250 and $350/sample if admissions were reduced by 5%over SOC and >10% with $650/sample. When costs of LT, death and admissions were varied, these cost-savings remained robust provided there was >2.1% reduction (range 1.3%-3.2%) for $250/sample, >2.9% (range 1.8%-4.4%) for $350/sample and >5.4% (range 3.3%-8.2%) for $650/sample. These cost-savings remained robust even when the assumed admission rate was varied for all sample cost values.

Conclusions: Gut microbiota analysis is cost-effective for predicting and potentially preventing 90-day admissions in cirrhosis over current standard of care. This cost-saving remained robust even after sensitivity analyses that varied the background admission rates.

RevDate: 2020-10-19

Purohit J, Chattopadhyay A, B Teli (2020)

Metagenomic Exploration of Plastic Degrading Microbes for Biotechnological Application.

Current genomics, 21(4):253-270.

Since the last few decades, the promiscuous and uncontrolled use of plastics led to the accumulation of millions of tons of plastic waste in the terrestrial and marine environment. It elevated the risk of environmental pollution and climate change. The concern arises more due to the reckless and unscientific disposal of plastics containing high molecular weight polymers, viz., polystyrene, polyamide, polyvinylchloride, polypropylene, polyurethane, and polyethylene, etc. which are very difficult to degrade. Thus, the focus is now paid to search for efficient, eco-friendly, low-cost waste management technology. Of them, degradation of non-degradable synthetic polymer using diverse microbial agents, viz., bacteria, fungi, and other extremophiles become an emerging option. So far, very few microbial agents and their secreted enzymes have been identified and characterized for plastic degradation, but with low efficiency. It might be due to the predominance of uncultured microbial species, which consequently remain unexplored from the respective plastic degrading milieu. To overcome this problem, metagenomic analysis of microbial population engaged in the plastic biodegradation is advisable to decipher the microbial community structure and to predict their biodegradation potential in situ. Advancements in sequencing technologies and bioinformatics analysis allow the rapid metagenome screening that helps in the identification of total microbial community and also opens up the scope for mining genes or enzymes (hydrolases, laccase, etc.) engaged in polymer degradation. Further, the extraction of the core microbial population and their adaptation, fitness, and survivability can also be deciphered through comparative metagenomic study. It will help to engineer the microbial community and their metabolic activity to speed up the degradation process.

RevDate: 2020-10-19

Raza S, Jo H, Kim J, et al (2020)

Metagenomic exploration of antibiotic resistome in treated wastewater effluents and their receiving water.

The Science of the total environment pii:S0048-9697(20)36284-7 [Epub ahead of print].

Environmental dissemination of antimicrobial resistance is a global health problem. Antimicrobial-resistant bacteria and antibiotic-resistant genes (ARGs) are constantly released into the environment through effluents (EFs) from wastewater treatment plants (WWTPs). Thus, requiring a better understanding of the selection and fate of ARGs in wastewater treatment processes. Therefore, we investigated the impacts of urban WWTP EFs on receiving water in the context of their resistomes and mobilomes. We used a HiSeq-based short read metagenomic approach to address the dynamics and diversity of ARGs in WWTP EF as well as the upstream (UP) and downstream (DN) river waters, followed by an investigation of plasmid-mediated ARGs. The abundance of ARGs at each site varied from 7.2 × 10-2 to 7.4 × 10-1 ARG copies per 16S rRNA gene copy, and EF samples showed the highest abundance, followed by DN and UP water samples. ARG diversity ranged from 121 to 686 types per site, and EF had the most diverse ARGs. Commonly identified ARGs in the EF and DN samples were clinically important and were absent in UP samples. The abundance of ARGs, mobile genetic elements (MGEs), and plasmid contigs found only in EF and DN were positively correlated with each other, indicating the importance of mobilomes in the dissemination of ARGs in the environment. Moreover, the proportions of plasmid-mediated ARGs was highest in the EF samples, followed by the DN and UP samples. These findings suggest that WWTP EF may act as a driving factor shaping the resistomes and mobilomes of receiving waters. In particular, a higher abundance of plasmid-mediated ARGs in WWTP EF suggests higher transmissibility in the DN environment.

RevDate: 2020-10-18

Satjarak A, Graham LE, Piotrowski MJ, et al (2020)

Shotgun metagenomics and microscopy indicate diverse cyanophytes, other bacteria, and microeukaryotes in the epimicrobiota of a northern Chilean wetland Nostoc (Cyanobacteria).

Journal of phycology [Epub ahead of print].

Prokaryotic Nostoc, one of the world's most conspicuous and widespread algal genera-like eukaryotic algae, plants, and animals-is known to support a microbiome that influences host ecological roles. Past taxonomic characterizations of surface microbiota (epimicrobiota) of free-living Nostoc sampled from freshwater systems employed 16S rRNA genes, typically amplicons. We compared taxa identified from 16S, 18S, 23S, and 28S rRNA gene sequences filtered from shotgun metagenomic sequence and used microscopy to illuminate epimicrobiota diversity for Nostoc sampled from a wetland in the northern Chilean Altiplano. Phylogenetic analysis and rRNA gene sequence abundance estimates indicated that the host was related to Nostoc punctiforme PCC 73102. Epimicrobiota were inferred to include 18 epicyanobacterial genera or uncultured taxa, six epieukaryotic algal genera, and 66 anoxygenic bacterial genera, all having average genomic coverage ≥ 90X. The epicyanobacteria Geitlerinemia, Oscillatoria, Phormidium, and an uncultured taxon were detected only by 16S rRNA gene; Gloeobacter and Pseudanabaena were detected using 16S and 23S; and Phormididesmis, Neosynechococcus, Symphothece, Aphanizomenon, Nodularia, Spirulina, Nodosilinea, Synechococcus, Cyanobium, and Anabaena (the latter corroborated by microscopy), plus two uncultured cyanobacterial taxa (JSC12, O77) were detected only by 23S rRNA. Three chlamydomonad and two heterotrophic stramenopiles genera were inferred from 18S; the streptophyte green alga Chaetosphaeridium globosum was detected by microscopy and 28S rRNA genes, but not 18S rRNA genes. Overall, >60% of epimicrobial taxa were detected by markers other than 16S rRNA genes. Some algal taxa observed microscopically were not detected from sequence data. Results indicate that multiple taxonomic markers derived from metagenomic sequence data and microscopy increase epimicrobiota detection.

RevDate: 2020-10-18

Ferrara M, Haidukowski M, D'Imperio M, et al (2020)

New insight into microbial degradation of mycotoxins during anaerobic digestion.

Waste management (New York, N.Y.), 119:215-225 pii:S0956-053X(20)30559-6 [Epub ahead of print].

Anaerobic digestion represents an interesting approach to produce biogas from organic waste materials contaminated by mycotoxins. In this study a shotgun metagenomic analysis of lab-scale bioreactors fed with mycotoxin-contaminated silage has been carried out to characterize the evolution of microbial community under the operating conditions and the key enzymatic activities responsible for mycotoxin degradation. The study was conducted at two different level of contamination for fumonisins and aflatoxin B1. After 15 days biogas production was not influenced by the presence of mycotoxins. Metagenomic analysis revealed that a high contamination rate of mycotoxins interfere with microbial diversity. Degradation of mycotoxins accounted in about 54% for aflatoxin B1 and 60% for fumonisins. The degradation activity of fumonisins resulted in the presence of partially hydrolyzed forms in both tested contamination levels. Accordingly, metagenomic functional analysis revealed the presence of two new carboxylesterase genes belonging to D. bacterium and P. bacterium putatively involved in fumonisin degradation.

RevDate: 2020-10-18

Dai H, Gao J, Li D, et al (2020)

Metagenomics combined with DNA-based stable isotope probing provide comprehensive insights of active triclosan-degrading bacteria in wastewater treatment.

Journal of hazardous materials, 404(Pt B):124192 pii:S0304-3894(20)32182-8 [Epub ahead of print].

The biotransformation of triclosan (TCS) during wastewater treatment occurred frequently, while little researches are known the identity of microorganisms involved in the biodegradation process. In this work, DNA-based stable isotope probing (DNA-SIP) was occupied to investigate the TCS assimilation microbes originated from a full-scale cyclic activated sludge system in Beijing. Results of TCS removal pathway showed that the TCS removal in nitrification process was mainly contributed by the metabolism of heterotrophic bacteria, accounting for about 18.54%. DNA-SIP assay indicated that Sphingobium dominated the degradation of TCS. Oligotyping analysis further indicated that oligotype GCTAAT and ATGTTA of Sphingobium played important roles in degrading TCS. Furthermore, the Kyoto Encyclopedia of Genes and Genomes functional abundance statistics based on PICRUSt2 showed that glutathione transferase was the most prevalent enzyme involved in TCS metabolism, and TCS might be removed through microbial carbon metabolism. Metagenomics made clear that Sphingobium might play irrelevant role on the propagation of antibiotics resistance genes (ARGs), even though, it could degrade TCS. Thauera and Dechloromonas were identified as the key hosts of most ARGs. This study revealed the potential metabolic pathway and microbial ecology of TCS biodegradation in nitrification process of wastewater treatment system.

RevDate: 2020-10-18

Xue W, Zhang C, Wang K, et al (2020)

Understanding the deterioration of fresh brown rice noodles from the macro and micro perspectives.

Food chemistry pii:S0308-8146(20)32183-X [Epub ahead of print].

The microbial compositions, quality characteristics, and structural changes in fresh brown rice noodles (FBRN) during storage were investigated. Total plate count and mold and yeast counts increased while the pH decreased during storage. Metagenomic sequencing revealed that the microbial composition of FBRN changed throughout storage. A comprehensive investigation of the variation in lipid content demonstrated that hydrolytic rancidity was responsible for lipid deterioration. LF-NMR showed an increase in the proportion of bound water and a decrease in the proportion of free water in FBRN. Moreover, significant changes in edible qualities were observed. The cooking loss increased three-fold and noodles hardness reduced by approximately 23%. Further, the high initial aldehyde content of FBRN diminished almost completely, while that of alcohols and esters increased, leading to significant flavor deterioration. The correlation and factor analysis suggested that the TPC and MY counts could be used as key indicators of FBRN deterioration.

RevDate: 2020-10-18

Borroni D, C Rocha de Lossada (2020)

Microbial keratitis: the clinical impact of metagenomic next-generation sequencing (mNGS).

RevDate: 2020-10-19

Campocasso A, B La Scola (2012)

Virus géants associés aux amibes.

Virologie (Montrouge, France), 16(1):6-17.

The discovery of Acanthamoeba polyphaga Mimivirus, a giant amoeba-associated virus less than a decade ago, has shattered the definition of what is a virus. With an exceptional size of 500 nm, a genome of more than 1 Mb, a particle containing both DNA and RNA, possibility to be infected by another virus are unusual characteristics that make it immediately exceptional. Since then, several giant viruses have been isolated such as Marseillevirus. It is highly probable that closely related viruses will be isolated as it is now understood that they were not previously isolated because they are not filterable. Environmental metagenomic studies suggest that these viruses are ubiquitous. The discovery of virophages, small viruses able to infect Mimivirus as bacteriophage infect bacteria, fuel the debate about the nature of viruses and their place in the evolution of life. Current works, especially genome sequencing of these new viruses, open new perspectives about evolution and lateral gene transfer with their host but also with bacteria and other viruses. The knowledge about these viruses is only at the first step and increasing interest for it suggests that we are only at the dawn of the understanding of their role in evolution and ecosystems regulation.

RevDate: 2020-10-17

Palombieri A, Di Profio F, Lanave G, et al (2020)

Molecular detection and characterization of Carnivore chaphamaparvovirus 1 in dogs.

Veterinary microbiology, 251:108878 pii:S0378-1135(20)31016-6 [Epub ahead of print].

Canine chaphamaparvovirus (CaChPV) is a newly recognised parvovirus discovered by metagenomic analysis during an outbreak of diarrhoea in dogs in Colorado, USA, in 2017 and more recently detected in diarrhoeic dogs in China. Whether the virus plays a role as canine pathogen and whether it is distributed elsewhere, in other geographical areas, is not known. We performed a case-control study to investigate the possible association of CaChPV with enteritis in dogs. CaChPV DNA was detected both in the stools of diarrhoeic dogs (1.9 %, 3/155) and of healthy animals (1.6 %, 2/120). All the CaChPV-infected dogs with diarrhea were mixed infected with other enteric viruses such as canine parvovirus (formerly CPV-2), canine bufavirus (CBuV) and canine coronavirus (CCoV), whilst none of the asymptomatic CaChPV positive animals resulted co-infected. The nearly full-length genome and the partial capsid protein (VP) gene of three canine strains, Te/36OVUD/19/ITA, Te/37OVUD/19/ITA and Te/70OVUD/19/ITA, were reconstructed. Upon phylogenetic analyses based on the NS1 and VP aa sequences, the Italian CaChPV strains tightly clustered with the American reference viruses. Distinctive residues could be mapped to the deduced variable regions of the VP of canine and feline chaphamaparvoviruses, considered as important markers of host range and pathogenicity for parvoviruses.

RevDate: 2020-10-19

Imchen M, R Kumavath (2020)

Metagenomic insights into the antibiotic resistome of mangrove sediments and their association to socioeconomic status.

Environmental pollution (Barking, Essex : 1987), 268(Pt A):115795 pii:S0269-7491(20)36484-8 [Epub ahead of print].

Mangrove sediments are prone to anthropogenic activities that could enrich antibiotics resistance genes (ARGs). The emergence and dissemination of ARGs are of serious concern to public health worldwide. Therefore, a comprehensive resistome analysis of global mangrove sediment is of paramount importance. In this study, we have implemented a deep machine learning approach to analyze the resistome of mangrove sediments from Brazil, China, Saudi Arabia, India, and Malaysia. Geography (RANOSIM = 39.26%; p < 0.005) as well as human intervention (RANOSIM = 16.92%; p < 0.005) influenced the ARG diversity. ARG diversity was also inversely correlated to the human development index (HDI) of the host country (R = -0.53; p < 0.05) rather than antibiotics consumption (p > 0.05). Several genes including multidrug efflux pumps were significantly (p < 0.05) enriched in the sites with human intervention. Resistome was consistently dominated by rpoB2 (19.26 ± 0.01%), multidrug ABC transporter (10.40 ± 0.23%), macB (8.84 ± 0.36n%), tetA (4.13 ± 0.35%), mexF (3.26 ± 0.19%), CpxR (2.93 ± 0.2%), bcrA (2.38 ± 0.24%), acrB (2.37 ± 0.18%), mexW (2.19 ± 0.17%), and vanR (1.99 ± 0.11%). Besides, mobile ARGs such as vanA, tet(48), mcr, and tetX were also detected in the mangrove sediments. Comparative analysis against terrestrial and ocean resistomes showed that the ocean ecosystem harbored the lowest ARG diversity (Chao1 = 71.12) followed by mangroves (Chao1 = 258.07) and terrestrial ecosystem (Chao1 = 294.07). ARG subtypes such as abeS and qacG were detected exclusively in ocean datasets. Likewise, rpoB2, multidrug ABC transporter, and macB, detected in mangrove and terrestrial datasets, were not detected in the ocean datasets. This study shows that the socioeconomic factors strongly determine the antibiotic resistome in the mangrove. Direct anthropogenic intervention in the mangrove environment also enriches antibiotic resistome.

RevDate: 2020-10-17

Wang M, Wang H, Zheng H, et al (2020)

A heat diffusion multilayer network approach for the identification of functional biomarkers in rumen methane emissions.

Methods (San Diego, Calif.) pii:S1046-2023(20)30221-8 [Epub ahead of print].

A better understanding of rumen microbial interactions is crucial for the study of rumen metabolism and methane emissions. Metagenomics-based methods can explore the relationship between microbial genes and metabolites to clarify the effect of microbial function on the host phenotype. This study investigated the rumen microbial mechanisms of methane metabolism in cattle by combining metagenomic data and network-based methods. Based on the relative abundance of 1461 rumen microbial genes and the main volatile fatty acids (VFAs), a multilayer heterogeneous network was constructed, and the functional modules associated with metabolite-microbial genes were obtained by heat diffusion. The PLS model by integrating data from VFAs and microbial genes explained 72.98% variation of methane emissions. Compared with single-layer networks, more previously reported biomarkers of methane prediction can be captured by the multilayer network. More biomarkers with the rank of top 20 topological centralities are from the PLS model of diffusion subset. The heat diffusion algorithm is different from the strategy used by the microbial metabolic system to understand methane phenotype. It inferred 24 novel biomarkers that were preferentially affected by changes in specific VFAs. Results showed that the heat diffusion multilayer network approach improved the understanding of the microbial patterns of VFA affecting methane emissions which represented by the functional genes.

RevDate: 2020-10-17

Yadav R, Rajput V, M Dharne (2020)

Functional metagenomic landscape of polluted river reveals potential genes involved in degradation of xenobiotic pollutants.

Environmental research pii:S0013-9351(20)31229-9 [Epub ahead of print].

Rapid industrialization contributes substantially to xenobiotic pollutants in rivers. As a result, most of the rivers traversing urban settlements are in significantly deteriorated conditions. These pollutants are recalcitrant, requiring robust catabolic machinery for their complete transformation into bioavailable and non-toxic by-products. Microbes are versatile dwellers that could adapt to such contaminants by using them as a source of nutrients during growth. However, efficient bioremediation requires an in-depth knowledge of microbial diversity and their metabolism related genes in the polluted niches. We employed MinION shotgun sequencing, to comprehend the biodegradation related genes and their function potential operating in the polluted urban riverine system of Western India. A vast number of catabolic genes were detected for the xenobiotic pollutants such as Benzoate, Nitrotoluene, Aminobenzoate, Drug metabolism, and Polycyclic Aromatic Hydrocarbons. Aerobic, and anaerobic catabolism genes, were mapped for their ability of degradation of xenobiotics. Interestingly, catabolism profiles of multiple aromatic compounds culminated into the Benzoate degradation pathway, suggesting it as a plausible central pathway for the autochthonous bacterial communities. Further mapping with RemeDB database, predicted plastic and dye degrading enzymes. Moreover, the diversity indices for the pollutant degrading enzymes suggested little variations (R2 value of 18%) between the city and non-city (outskirts of city limits) riverine stretch indicating the impact of industrialization in the outskirts of the city stretch as well. Altogether, this study would serve as a preliminary baseline for future explorations concerning river cleaning programs and also exploiting such microbes for bioremediation applications.

RevDate: 2020-10-17

Bräuer S, Basiliko N, Siljanen H, et al (2020)

Methanogenic archaea in peatlands.

FEMS microbiology letters pii:5928548 [Epub ahead of print].

Methane emission feedbacks in wetlands are predicted to influence global climate under climate change and other anthropogenic stressors. Herein, we review the taxonomy and physiological ecology of the microorganisms responsible for methane production in peatlands. Common in peat soils are five of the eight described orders of methanogens spanning three phyla (Euryarchaeota, Halobacterota and Thermoplasmatota). The phylogenetic affiliation of sequences found in peat suggest that members of the thus-far-uncultivated group Candidatus Bathyarchaeota (representing a fourth phylum) may be involved in methane cycling, either anaerobic oxidation of methane and/or methanogenesis, as at least a few organisms within this group contain the essential gene, mcrA, according to metagenomic data. Methanogens in peatlands are notoriously challenging to enrich and isolate; thus, much remains unknown about their physiology and how methanogen communities will respond to environmental changes. Consistent patterns of changes in methanogen communities have been reported across studies in permafrost peatland thaw where the resulting degraded feature is thermokarst. However much remains to be understood regarding methanogen community feedbacks to altered hydrology and warming in other contexts, enhanced atmospheric pollution (N, S, metals) loading, and direct anthropogenic disturbances to peatlands like drainage, horticultural peat extraction, forestry, and agriculture, as well as post-disturbance reclamation.

RevDate: 2020-10-19

de Koning W, Miladi M, Hiltemann S, et al (2020)

NanoGalaxy: Nanopore long-read sequencing data analysis in Galaxy.

GigaScience, 9(10):.

BACKGROUND: Long-read sequencing can be applied to generate very long contigs and even completely assembled genomes at relatively low cost and with minimal sample preparation. As a result, long-read sequencing platforms are becoming more popular. In this respect, the Oxford Nanopore Technologies-based long-read sequencing "nanopore" platform is becoming a widely used tool with a broad range of applications and end-users. However, the need to explore and manipulate the complex data generated by long-read sequencing platforms necessitates accompanying specialized bioinformatics platforms and tools to process the long-read data correctly. Importantly, such tools should additionally help democratize bioinformatics analysis by enabling easy access and ease-of-use solutions for researchers.

RESULTS: The Galaxy platform provides a user-friendly interface to computational command line-based tools, handles the software dependencies, and provides refined workflows. The users do not have to possess programming experience or extended computer skills. The interface enables researchers to perform powerful bioinformatics analysis, including the assembly and analysis of short- or long-read sequence data. The newly developed "NanoGalaxy" is a Galaxy-based toolkit for analysing long-read sequencing data, which is suitable for diverse applications, including de novo genome assembly from genomic, metagenomic, and plasmid sequence reads.

CONCLUSIONS: A range of best-practice tools and workflows for long-read sequence genome assembly has been integrated into a NanoGalaxy platform to facilitate easy access and use of bioinformatics tools for researchers. NanoGalaxy is freely available at the European Galaxy server https://nanopore.usegalaxy.eu with supporting self-learning training material available at https://training.galaxyproject.org.

RevDate: 2020-10-17

Li Y, Zhu Y, Wei H, et al (2020)

Study on the Diversity and Function of Gut Microbiota in Pigs Following Long-Term Antibiotic and Antibiotic-Free Breeding.

Current microbiology pii:10.1007/s00284-020-02240-8 [Epub ahead of print].

In-feed antibiotics can influence intestinal microbial structures in born and early-life within a period. However, the impact of antibiotics on gut microbiota during long-term antibiotic-free and antibiotic breeding at porcine-fattening phase have not been studied extensively so far. Here, we conducted a systematic 16S rRNA gene sequencing-based study combined with metagenomic analysis to reveal the variation of diversity and function of gut microbiota between antibiotic-free (treatment group, TG) and antibiotic (a mixture of flavomycin and enramycin, control group, CG) breeding at various stages of fattening pigs. In the present study, Bacteroidetes, Firmicutes, and Proteobacteria phyla were the core microbiomes in fattening pig gut microbiota. The ratio between Firmicutes and Bacteroidetes significantly increased with age (P = 0.03). TG showed significantly higher relative abundance of Proteobacteria and Fibrobacteres phyla than CG. The microbial community can be divided into several notably clustered blocks based on cooperative and competitive correlations. These blocks centered on numerous special genera, which play essential roles in body development and disease prevention. TG showed obviously higher proportions of metabolic pathways related to metabolism, endocrine system, nervous system and excretory system, but pathways included carbohydrate metabolism and immune system diseases in CG. Collectively, this study has comprehensively demonstrated microbial diversities, differences and correlations among gut microbiota, microbial metabolism and gene functions during long-term antibiotic-free breeding. This work provides a novel resource and information with positive implications for pig husbandry production and disease prevention.

RevDate: 2020-10-17

Ding X, Lan W, Wu J, et al (2020)

Correction to: Microbiome and nitrate removal processes by microorganisms on the ancient Preah Vihear temple of Cambodia revealed by metagenomics and N-15 isotope analyses.

The published online version contains mistake for the author the authors correction to change the name from Clara Uriz to Clara Urzì was missed.

RevDate: 2020-10-17

Guerrero LD, Pérez MV, Orellana E, et al (2020)

Long-run bacteria-phage coexistence dynamics under natural habitat conditions in an environmental biotechnology system.

The ISME journal pii:10.1038/s41396-020-00802-z [Epub ahead of print].

Bacterial viruses are widespread and abundant across natural and engineered habitats. They influence ecosystem functioning through interactions with their hosts. Laboratory studies of phage-host pairs have advanced our understanding of phenotypic and genetic diversification in bacteria and phages. However, the dynamics of phage-host interactions have been seldom recorded in complex natural environments. We conducted an observational metagenomic study of the dynamics of interaction between Gordonia and their phages using a three-year data series of samples collected from a full-scale wastewater treatment plant. The aim was to obtain a comprehensive picture of the coevolution dynamics in naturally evolving populations at relatively high time resolution. Coevolution was followed by monitoring changes over time in the CRISPR loci of Gordonia metagenome-assembled genome, and reciprocal changes in the viral genome. Genome-wide analysis indicated low strain variability of Gordonia, and almost clonal conservation of the trailer end of the CRISPR loci. Incorporation of newer spacers gave rise to multiple coexisting bacterial populations. The host population carrying a shorter CRISPR locus that contain only ancestral spacers, which has not acquired newer spacers against the coexisting phages, accounted for more than half of the total host abundance in the majority of samples. Phages genome co-evolved by introducing directional changes, with no preference for mutations within the protospacer and PAM regions. Metagenomic reconstruction of time-resolved variants of host and viral genomes revealed how the complexity at the population level has important consequences for bacteria-phage coexistence.

RevDate: 2020-10-17

Babiker A, Bradley HL, Stittleburg VD, et al (2020)

Metagenomic sequencing to detect respiratory viruses in persons under investigation for COVID-19.

Journal of clinical microbiology pii:JCM.02142-20 [Epub ahead of print].

Broad testing for respiratory viruses among persons under investigation (PUIs) for SARS-CoV-2 has been performed inconsistently, limiting our understanding of alternative viral infections and co-infections in these patients. RNA metagenomic next-generation sequencing (mNGS) offers an agnostic tool for the detection of both SARS-CoV-2 and other RNA respiratory viruses in PUIs. Herein, we used RNA mNGS to assess the frequencies of alternative viral infections in SARS-CoV-2 RT-PCR negative PUIs (n=30) and viral co-infections in SARS-CoV-2 RT-PCR positive PUIs (n=45). mNGS identified all viruses detected by routine clinical testing (Influenza A (N=3), Human metapneumovirus (N=2), Human coronavirus OC43 (N=2) and Human coronavirus HKU1(N=1)). mNGS also identified both co-infections (1, 2.2%) and alternative viral infections (4, 13.3%) that were not detected by routine clinical workup (Respiratory syncytial virus (N=3), Human metapneumovirus (N=1), Human coronavirus NL63 (N=1)). Among SARS-CoV-2 RT-PCR positive PUIs, lower cycle threshold (CT) values correlated with greater SARS-CoV-2 read recovery by mNGS (R2: 0.65, p-value: <0.001). Our results suggest that current broad-spectrum molecular testing algorithms identify most respiratory viral infections among SARS-CoV-2 PUIs, when available and implemented consistently.

RevDate: 2020-10-17

Mori JF, RA Kanaly (2020)

Multispecies diesel fuel biodegradation and niche formation are ignited by pioneer hydrocarbon-utilizing proteobacteria in a soil bacterial consortium.

Applied and environmental microbiology pii:AEM.02268-20 [Epub ahead of print].

A soil bacterial consortium that was grown on diesel fuel and consisted of more than 10 members from different genera was maintained through repetitive sub-culturing and was utilized as a practical model to investigate a bacterial community that was continuously exposed to petroleum hydrocarbons. Through metagenomics analyses, consortium member isolation, growth assays and metabolite identification which supported the linkage of genomic data and functionality, two pioneering genera, Sphingobium and Pseudomonas, whose catabolic capabilities were differentiated, were found to be responsible for the creation of specialized ecological niches that were apparently occupied by other bacterial members for survival within the consortium. Co-existing genera, Achromobacter and Cupriavidus, maintained their existence in the consortium through metabolic dependencies by utilizing hydrocarbon biotransformation products of pioneer metabolism which was confirmed through growth tests and identification of biotransformation products of the isolated strains. Pioneering Sphingobium and Pseudomonas spp. utilized relatively water insoluble hydrocarbon parent compounds and facilitated the development of a consortium community structure that resulted in creation of niches in response to diesel fuel exposure which were created through the production of more water soluble biotransformation products available to co-colonizers. That these and other organisms were still present in the consortium after multiple transfers spanning 15 years, provided evidence for these ecological niches. Member survival through occupation of these niches led to robustness of each group within the multispecies bacterial community. Overall, these results contribute to our understanding of the complex ecological relationships that may evolve during prokaryotic hydrocarbon pollutant biodegradation.Importance There are few metagenome studies that have explored soil consortia maintained on a complex hydrocarbon substrate after the community interrelationships were formed. A soil bacterial consortium maintained on diesel fuel was utilized as a practical model to investigate bacterial community relationships through metagenomics analyses, consortium member isolation, growth assays and metabolite identification which supported the linkage of genomic data and functionality. Two pioneering genera were responsible for biodegradation of aromatics and alkanes by initiating biotransformation and thereby created specialized niches that were populated by other members. A model that represents these relationships was constructed which contributes to our understanding of the complex ecological relationships that evolve during prokaryotic hydrocarbon pollutant biodegradation.

RevDate: 2020-10-17

Co R, LA Hug (2020)

Guest commentary: A need for improved cellulase identification from metagenomic sequence data.

Applied and environmental microbiology pii:AEM.01928-20 [Epub ahead of print].

Improved sequencing technologies and the maturation of metagenomic approaches allow identification of gene variants with potential industrial applications, including cellulases. Cellulase identification from metagenomic environmental surveys is complicated by inconsistent nomenclature and multiple categorization systems. Here, we summarize the current classification and nomenclature systems, with recommendations for improvements to these systems. Addressing the described issues will strengthen annotation of cellulose-active enzymes from environmental sequence datasets - a rapidly growing resource in environmental and applied microbiology.

RevDate: 2020-10-17

Boonyapakron K, Chitnumsub P, Kanokratana P, et al (2020)

Enhancement of catalytic performance of a metagenome-derived thermophilic oligosaccharide-specific xylanase by binding module removal and random mutagenesis.

Journal of bioscience and bioengineering pii:S1389-1723(20)30357-1 [Epub ahead of print].

Xylo-oligosaccharide (XO) is a promising pre-biotic with applications in food, feed and healthcare products. XO can be produced by enzymatic digestion of xylan with xylanase. In this study, we aimed to improve the biochemical properties relevant to catalysis and kinetics of X11, a thermophilic glycosyl hydrolase (GH) family 11 endo-β-1,4-xylanase derived from a metagenomic library isolated from sugarcane bagasse, under high-temperature conditions preferred for XO synthesis. Removal of a carbohydrate-binding module (X11C) resulted in 6.5 fold greater catalytic efficiency. X11C was further improved by a Pro71Thr mutation in the X11P variant obtained from a random mutagenesis library, which exhibited 15.9 fold greater catalytic efficiency compared with wild-type X11 under the enzyme's optimal conditions of 80°C and pH 6.0. Homology modeling suggested that the improved performance of X11P could be attributed to formation of an extra H-bond between Thr71 and Ser75, which stabilizes the key catalytic residue Glu180 at the active pocket and β-sheet layers and agrees with the respective increase in melting temperature (Tm) where X11P >X11C >X11 as determined by differential scanning fluorimetry. The X11P variant was tested for hydrolysis of beechwood xylan, which showed X6 as the major product followed by X3 and X4 XOs. The highest yield of 5.5 g total XOs product/mg enzyme was observed for X11P, equivalent to 3.7 fold higher than that of wild-type with XO production of >800 mg/g xylan. The X11P enzyme could be developed as a thermophilic biocatalyst for XO synthesis in biorefineries.

RevDate: 2020-10-19

Khorraminezhad L, Leclercq M, Droit A, et al (2020)

Statistical and Machine-Learning Analyses in Nutritional Genomics Studies.

Nutrients, 12(10): pii:nu12103140.

Nutritional compounds may have an influence on different OMICs levels, including genomics, epigenomics, transcriptomics, proteomics, metabolomics, and metagenomics. The integration of OMICs data is challenging but may provide new knowledge to explain the mechanisms involved in the metabolism of nutrients and diseases. Traditional statistical analyses play an important role in description and data association; however, these statistical procedures are not sufficiently enough powered to interpret the large integrated multiple OMICs (multi-OMICS) datasets. Machine learning (ML) approaches can play a major role in the interpretation of multi-OMICS in nutrition research. Specifically, ML can be used for data mining, sample clustering, and classification to produce predictive models and algorithms for integration of multi-OMICs in response to dietary intake. The objective of this review was to investigate the strategies used for the analysis of multi-OMICs data in nutrition studies. Sixteen recent studies aimed to understand the association between dietary intake and multi-OMICs data are summarized. Multivariate analysis in multi-OMICs nutrition studies is used more commonly for analyses. Overall, as nutrition research incorporated multi-OMICs data, the use of novel approaches of analysis such as ML needs to complement the traditional statistical analyses to fully explain the impact of nutrition on health and disease.

RevDate: 2020-10-19

Ciulli S, Volpe E, Sirri R, et al (2020)

Multifactorial Causes of Chronic Mortality in Juvenile Sturgeon (Huso huso).

Animals : an open access journal from MDPI, 10(10): pii:ani10101866.

This investigation focused on an episode of chronic mortality observed in juvenile Huso huso sturgeons. The examined subjects underwent pathological, microbiological, molecular, and chemical investigations. Grossly severe body shape deformities, epaxial muscle softening, and multifocal ulcerative dermatitis were the main observed findings. The more constant histopathologic findings were moderate to severe rarefaction and disorganization of the lymphohematopoietic lymphoid tissues, myofiber degeneration, atrophy and interstitial edema of skeletal epaxial muscles, and degeneration and atrophy of the gangliar neurons close to the myofibers. Chemical investigations showed a lower selenium concentration in affected animals, suggesting nutritional myopathy. Other manifestations were nephrocalcinosis and splenic vessel wall hyalinosis. Septicemia due to bacteria such as Aeromonas veronii, Shewanella putrefaciens, Citrobacter freundii, Chryseobacterium sp., and pigmented hyphae were found. No major sturgeon viral pathogens were detected by classical methods. Next-generation sequencing (NGS) analysis confirmed the absence of viral pathogens, with the exception of herpesvirus, at the order level; also, the presence of Aeromonas veronii and Shewanella putrefaciens was confirmed at the family level by the metagenomic classification of NGS data. In the absence of a primary yet undetected biological cause, it is supposed that environmental stressors, including nutritional imbalances, may have led to immune system impairment, facilitating the entry of opportunistic bacteria and mycotic hyphae.

RevDate: 2020-10-16

De Filippis F, Pasolli E, D Ercolini (2020)

Newly Explored Faecalibacterium Diversity Is Connected to Age, Lifestyle, Geography, and Disease.

Current biology : CB pii:S0960-9822(20)31433-0 [Epub ahead of print].

Faecalibacterium is prevalent in the human gut and a promising microbe for the development of next-generation probiotics (NGPs) or biotherapeutics. Analyzing reference Faecalibacterium genomes and almost 3,000 Faecalibacterium-like metagenome-assembled genomes (MAGs) reconstructed from 7,907 human and 203 non-human primate gut metagenomes, we identified the presence of 22 different Faecalibacterium-like species-level genome bins (SGBs), some further divided in different strains according to the subject geographical origin. Twelve SGBs are globally spread in the human gut and show different genomic potential in the utilization of complex polysaccharides, suggesting that higher SGB diversity may be related with increased utilization of plant-based foods. Moreover, up to 11 different species may co-occur in the same subject, with lower diversity in Western populations, as well as intestinal inflammatory states and obesity. The newly explored Faecalibacterium diversity will be able to support the choice of strains suitable as NGPs, guided by the consideration of the differences existing in their functional potential.

RevDate: 2020-10-16

Rozenberg A, Oppermann J, Wietek J, et al (2020)

Lateral Gene Transfer of Anion-Conducting Channelrhodopsins between Green Algae and Giant Viruses.

Current biology : CB pii:S0960-9822(20)31426-3 [Epub ahead of print].

Channelrhodopsins (ChRs) are light-gated ion channels widely used as optogenetic tools for manipulating neuronal activity. The currently characterized ChR families include green algal and cryptophyte cation-conducting ChRs (CCRs) and cryptophyte, haptophyte, and stramenopile anion-conducting ChRs (ACRs). Here, we report the discovery of a new family of phylogenetically distinct ChRs encoded by marine giant viruses and acquired from their unicellular green algal hosts. These previously unknown viral and green algal ChRs act as ACRs when expressed in cultured neuroblastoma-derived cells and are likely involved in behavioral responses to light.

RevDate: 2020-10-16

Tiew PY, Jaggi TK, Chan LLY, et al (2020)

The airway microbiome in COPD, bronchiectasis and bronchiectasis-COPD overlap.

The clinical respiratory journal [Epub ahead of print].

OBJECTIVE: To review the airway microbiome in chronic obstructive pulmonary disease (COPD), bronchiectasis and bronchiectasis-COPD overlap (BCO).

Relevant studies were selected from PubMed, Google scholar, EMBASE and Web of Science. All studies involving human microbiomes, published in the English language, and using the search terms "COPD", "Chronic Obstructive Pulmonary Disease", "Bronchiectasis", "BCO" or "Bronchiectasis and COPD overlap", AND "microbiome", "mycobiome" or "metagenomics" were included.

RESULTS: Despite variability in sampling methods and specimen types used, microbiome composition remains relatively comparable in COPD and bronchiectasis with prominence of Proteobacteria, Firmicutes and Bacteroidetes. Alterations to airway microbiomes occur in association to disease severity and/or exacerbations in COPD and bronchiectasis. Decreased alpha diversity and Haemophilus-predominant microbiomes are associated with poorer survival in COPD, while, in bronchiectasis, Pseudomonas-predominant microbiomes demonstrate high exacerbation frequency and greater symptom burden while Aspergillus-dominant mycobiome profiles associate with exacerbations. The role of the microbiome in BCO remains understudied.

CONCLUSION: Use of next generation sequencing has revolutionised our detection and understanding of the airway microbiome in chronic respiratory diseases such as COPD and bronchiectasis. Targeted amplicon sequencing reveals important associations between the respiratory microbiome and disease outcome while metagenomics may elucidate functional pathways. How best to apply this information into patient care, monitoring and treatment however remains challenging and necessitates further study.

RevDate: 2020-10-16

Liu L, He Y, Wang K, et al (2020)

Metagenomics approach to the intestinal microbiome structure and function in high fat diet-induced obesity in mice fed with conjugated linoleic acid (CLA).

Food & function [Epub ahead of print].

In this study, a high fat diet induced obesity mouse model (DIO) was used to investigate the modulatory effect of high purity conjugated linoleic acid (CLA) on the intestinal microbiota. CLA was prepared by a simulated moving bed chromatography system and its influence on the gut microbes was analyzed by 16S amplicon V3-V4 region analysis. We observed a significant increase in the bacterial biodiversity and the abundance of genera of butyrate- and acetate-producing bacteria. After taking CLA for 6 weeks, the abundance of Bacteroides in the intestines of mice greatly increased, while the abundance of Firmicutes decreased. The corresponding decrease in the Firmicutes/Bacteroidetes ratio reflected a positive modulatory effect of CLA on the intestinal microbiota. In addition, KEGG pathways for the nucleotide metabolism, metabolism of terpenoids and polyketides and lipid metabolism were among the most differentially expressed genes after CLA intervention. The current study revealed that CLA can be used as a functional food component with potential therapeutic value to prevent obesity-related metabolic disorders by manipulating the intestinal microbiota.

RevDate: 2020-10-16

Mallick H, Bucci V, L An (2020)

Editorial: Statistical and Computational Methods for Microbiome Multi-Omics Data.

Frontiers in genetics, 11:927.

RevDate: 2020-10-16

Wang Q, Wu B, Yang D, et al (2020)

Optimal specimen type for accurate diagnosis of infectious peripheral pulmonary lesions by mNGS.

BMC pulmonary medicine, 20(1):268 pii:10.1186/s12890-020-01298-1.

BACKGROUND: Reports on the application of metagenomic next-generation sequencing (mNGS) to the diagnosis of peripheral pulmonary lesions (PPLs) are scarce. There have been no studies investigating the optimal specimen type for mNGS.

METHODS: We used mNGS to detect pathogens in matched transbronchial lung biopsy (TBLB), bronchoalveolar lavage fluid (BALF), and bronchial needle brushing (BB) specimens from 39 patients suspected of having infectious PPLs. We explored differences in microbial composition and diagnostic accuracy of mNGS for the 3 specimen types.

RESULTS: mNGS was more sensitive than conventional culture for detection of bacteria and fungi in TBLB, BALF, and BB specimens, with no difference in the sensitivity of mNGS across the different specimen types. mNGS showed higher sensitivity for fungi or uncategorized pulmonary pathogens in TBLB+BALF+BB compared to TBLB but not BALF or BB specimens. There were no significant differences between the 3 specimen types in the relative abundance of pathogens, or between TBLB and BB specimens in the relative abundance of 6 common lower respiratory tract commensals.

CONCLUSIONS: mNGS has a higher sensitivity than the conventional culture method for detecting pathogens in TBLB, BALF, or BB specimens. mNGS of BB samples is a less invasive alternative to TBLB for the diagnosis of infectious PPLs.

RevDate: 2020-10-16

Golob JL, SS Minot (2020)

In silico benchmarking of metagenomic tools for coding sequence detection reveals the limits of sensitivity and precision.

BMC bioinformatics, 21(1):459 pii:10.1186/s12859-020-03802-0.

BACKGROUND: High-throughput sequencing can establish the functional capacity of a microbial community by cataloging the protein-coding sequences (CDS) present in the metagenome of the community. The relative performance of different computational methods for identifying CDS from whole-genome shotgun sequencing is not fully established.

RESULTS: Here we present an automated benchmarking workflow, using synthetic shotgun sequencing reads for which we know the true CDS content of the underlying communities, to determine the relative performance (sensitivity, positive predictive value or PPV, and computational efficiency) of different metagenome analysis tools for extracting the CDS content of a microbial community. Assembly-based methods are limited by coverage depth, with poor sensitivity for CDS at < 5X depth of sequencing, but have excellent PPV. Mapping-based techniques are more sensitive at low coverage depths, but can struggle with PPV. We additionally describe an expectation maximization based iterative algorithmic approach which we show to successfully improve the PPV of a mapping based technique while retaining improved sensitivity and computational efficiency.

CONCLUSION: Our benchmarking approach reveals the trade-offs of assembly versus alignment-based approaches and the relative performance of specific implementations when one wishes to extract the protein coding capacity of microbial communities.

RevDate: 2020-10-19

Chakraborty J, Rajput V, Sapkale V, et al (2020)

Spatio-temporal resolution of taxonomic and functional microbiome of Lonar soda lake of India reveals metabolic potential for bioremediation.

Chemosphere, 264(Pt 2):128574 pii:S0045-6535(20)32769-7 [Epub ahead of print].

Lonar Lake, India; a hypersaline and hyperalkaline extremophilic ecosystem having a unique microbial population has been rarely explored for bioremediation aspects. MinION-based shotgun sequencing was used to comprehensively compare the microbial diversity and functional potential of xenobiotic degradation pathways with seasonal changes. Proteobacteria and Firmicutes were prevalent bacterial phyla in the pre-monsoon and post-monsoon samples. Functional analysis from SEED-subsystem and KEGG database revealed 28 subsystems and 18 metabolic pathways for the metabolism of aromatic compounds and xenobiotic biodegradation respectively. Occurrence of N-phenyl alkanoic, benzoate, biphenyl, chloroaromatic, naphthalene, and phenol degradation genes depicted varied abundance in the pre-monsoon and post-monsoon samples. Further, KEGG analysis indicated nitrotoluene degradation pathway (ko00633) abundant in post-monsoon samples, and the benzoate degradation pathway (ko00362) predominant in 19LN4S (pre-monsoon) than 18LN7S (post-monsoon) samples. The abundant genes for benzoate degradation were pcaI: 3-oxoadipate CoA-transferase, alpha subunit, pcaH: protocatechuate 3,4-dioxygenase, beta subunit, and pcaB: 3-carboxy-cis, cis-muconate cycloisomerase, and 4-oxalocrotonate tautomerase. This metagenomic study provides a unique blueprint of hitherto unexplored xenobiotic biodegradation genes/pathways in terms of seasonal variations in the Lonar Lake, and warrants active exploitation of microbes for bioremediation purposes.

RevDate: 2020-10-19

Zhao Y, Hu J, Yang W, et al (2020)

The long-term effects of using nitrite and urea on the enrichment of comammox bacteria.

The Science of the total environment, 755(Pt 2):142580 pii:S0048-9697(20)36109-X [Epub ahead of print].

The discovery of complete ammonia oxidizer (comammox) was a breakthrough in the study of nitrification. However, slow growth of comammox bacteria makes it challenging to distinguish them from traditional ammonia oxidizing microorganisms. Genomic data indicated that comammox bacteria encoded genes that can metabolize urea and had higher nitrite tolerance, which could only be found in several ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB). This implies that using nitrite and urea as nitrogen sources may accelerate comammox bacteria's enrichment efficiency. In this study, two reactors using nitrite and urea as substrates, respectively, were operated for 390 days. At the end of cultivation, the reactor fed with urea exhibited higher nitrification potential than the reactor fed with nitrite. Comammox bacteria outcompeted AOA and AOB, regardless of whether they were cultured with nitrite or urea. Using nitrite can improve the proportion of comammox amoA to total amoA of 92%, while using urea may increase the proportion of comammox bacteria among total bacteria to 14.2%. Metagenomic results implied that nitrite was converted to ammonia by nitrate reduction and absorbed by comammox bacteria. On the other hand, urea may be directly utilized as substrate. These results demonstrated that using different nitrogen sources caused niche differentiation of comammox bacteria, AOA, and AOB. Using nitrite can increase the relative abundance of comammox amoA to total amoA, while using urea can increase the quantity of comammox amoA. Comammox bacteria were dominant among ammonia oxidizing microorganisms for both nitrite and urea cultures.

RevDate: 2020-10-16

Schmidt B, A Hildebrandt (2020)

Deep learning in next-generation sequencing.

Drug discovery today pii:S1359-6446(20)30415-3 [Epub ahead of print].

Next-generation sequencing (NGS) methods lie at the heart of large parts of biological and medical research. Their fundamental importance has created a continuously increasing demand for processing and analysis methods of the data sets produced, addressing questions such as variant calling, metagenomic classification and quantification, genomic feature detection, or downstream analysis in larger biological or medical contexts. In addition to classical algorithmic approaches, machine-learning (ML) techniques are often used for such tasks. In particular, deep learning (LD) methods that use multilayered artificial neural networks (ANNs) for supervised, semisupervised, and unsupervised learning have gained significant traction for such applications. Here, we highlight important network architectures, application areas, and DL frameworks in a NGS context.

RevDate: 2020-10-15

Miyani B, McCall C, I Xagoraraki (2020)

High Abundance of Human Herpesvirus 8 in Wastewater from a Large Urban Area.

Journal of applied microbiology [Epub ahead of print].

This study assesses the diversity and abundance of Human Herpesviruses (HHVs) in the influent of an urban wastewater treatment plant by using shotgun sequencing, metagenomic analysis, and qPCR.

METHODS AND RESULTS: Influent wastewater samples were collected from the three interceptors that serve the City of Detroit and Wayne, Macomb and Oakland counties between November 2017 to February 2018. The samples were subjected to a series of processes to concentrate viruses which were further sequenced and amplified using qPCR. All nine types of human herpesviruses were detected in wastewater. Human Herpesvirus 8 (HHV-8), known as Kaposi's sarcoma herpesvirus, which is only prevalent in 5-10% of USA population, was found to be the most abundant followed by Human Herpesvirus 3 or Varicella-zoster virus.

CONCLUSIONS: The high abundance of HHV-8 in the Detroit metropolitan area may be attributed to the HIV-AIDS outbreak that was ongoing in Detroit during the sampling period.

The approach described in this paper can be used to establish a baseline of viruses secreted by the community as a whole. Sudden changes in the baseline would identify changes in community health and immunity.

RevDate: 2020-10-15

Li J, Zuo K, Zhang J, et al (2020)

Shifts in gut microbiome and metabolome are associated with risk of recurrent atrial fibrillation.

Journal of cellular and molecular medicine [Epub ahead of print].

Alternations of gut microbiota (GM) in atrial fibrillation (AF) with elevated diversity, perturbed composition and function have been described previously. The current work aimed to assess the association of GM composition with AF recurrence (RAF) after ablation based on metagenomic sequencing and metabolomic analyses and to construct a GM-based predictive model for RAF. Compared with non-AF controls (50 individuals), GM composition and metabolomic profile were significantly altered between patients with recurrent AF (17 individuals) and non-RAF group (23 individuals). Notably, discriminative taxa between the non-RAF and RAF groups, including the families Nitrosomonadaceae and Lentisphaeraceae, the genera Marinitoga and Rufibacter and the species Faecalibacterium sp CAG:82, Bacillus gobiensis and Desulfobacterales bacterium PC51MH44, were selected to construct a taxonomic scoring system based on LASSO analysis. After incorporating the clinical factors of RAF, taxonomic score retained a significant association with RAF incidence (HR = 2.647, P = .041). An elevated AUC (0.954) and positive NRI (1.5601) for predicting RAF compared with traditional clinical scoring (AUC = 0.6918) were obtained. The GM-based taxonomic scoring system theoretically improves the model performance, and the nomogram and decision curve analysis validated the clinical value of the predicting model. These data provide novel possibility that incorporating the GM factor into future recurrent risk stratification.

RevDate: 2020-10-15

Yang J, Wang H, Zhang X, et al (2020)

Viral metagenomic identification of a novel anellovirus in blood sample of a child with atopic dermatitis.

Journal of medical virology [Epub ahead of print].

Here, using viral metagenomics, a novel anellovirus with strain name HuAV-zj-ad1 was detected in blood sample from a child with atopic dermatitis. The complete genome sequence of HuAV-zj-ad1 was determined and fully characterized. The circular genome of HuAV-zj-ad1 is 2841 nt in length and includes four polyprotein ORFs. Phylogenetic analysis and pairwise sequence comparisons based on the amino acid sequences of ORF1, ORF2, ORF3, ORF4 indicated that HuAV-zj-ad1 belonged to a novel species within the genus Betatorquevirus. PCR screening results showed this anellovirus was not present 50 blood samples from normal children. Whether this novel species of anellovirus has association with a certain disease needs further study. This article is protected by copyright. All rights reserved.

RevDate: 2020-10-15

Kalantar KL, Carvalho T, de Bourcy CFA, et al (2020)

IDseq-An open source cloud-based pipeline and analysis service for metagenomic pathogen detection and monitoring.

GigaScience, 9(10):.

BACKGROUND: Metagenomic next-generation sequencing (mNGS) has enabled the rapid, unbiased detection and identification of microbes without pathogen-specific reagents, culturing, or a priori knowledge of the microbial landscape. mNGS data analysis requires a series of computationally intensive processing steps to accurately determine the microbial composition of a sample. Existing mNGS data analysis tools typically require bioinformatics expertise and access to local server-class hardware resources. For many research laboratories, this presents an obstacle, especially in resource-limited environments.

FINDINGS: We present IDseq, an open source cloud-based metagenomics pipeline and service for global pathogen detection and monitoring (https://idseq.net). The IDseq Portal accepts raw mNGS data, performs host and quality filtration steps, then executes an assembly-based alignment pipeline, which results in the assignment of reads and contigs to taxonomic categories. The taxonomic relative abundances are reported and visualized in an easy-to-use web application to facilitate data interpretation and hypothesis generation. Furthermore, IDseq supports environmental background model generation and automatic internal spike-in control recognition, providing statistics that are critical for data interpretation. IDseq was designed with the specific intent of detecting novel pathogens. Here, we benchmark novel virus detection capability using both synthetically evolved viral sequences and real-world samples, including IDseq analysis of a nasopharyngeal swab sample acquired and processed locally in Cambodia from a tourist from Wuhan, China, infected with the recently emergent SARS-CoV-2.

CONCLUSION: The IDseq Portal reduces the barrier to entry for mNGS data analysis and enables bench scientists, clinicians, and bioinformaticians to gain insight from mNGS datasets for both known and novel pathogens.

RevDate: 2020-10-15

Eriksen AMH, Nielsen TK, Matthiesen H, et al (2020)

Bone biodeterioration-The effect of marine and terrestrial depositional environments on early diagenesis and bone bacterial community.

PloS one, 15(10):e0240512 pii:PONE-D-20-15946.

Bacteria play an important role in the degradation of bone material. However, much remains to be learnt about the structure of their communities in degrading bone, and how the depositional environment influences their diversity throughout the exposure period. We genetically profiled the bacterial community in an experimental series of pig bone fragments (femur and humeri) deposited at different well-defined environments in Denmark. The bacterial community in the bone fragments and surrounding depositional environment were studied over one year, and correlated with the bioerosion damage patterns observed microscopically in the bones. We observed that the bacterial communities within the bones were heavily influenced by the local microbial community, and that the general bone microbial diversity increases with time after exposure. We found the presence of several known collagenase producing bacterial groups, and also observed increases in the relative abundance of several of these in bones with tunneling. We anticipate that future analyses using shotgun metagenomics on this and similar datasets will be able to provide insights into mechanisms of microbiome driven bone degradation.

RevDate: 2020-10-14

Chen Y, Neilson JW, Kushwaha P, et al (2020)

Life-history strategies of soil microbial communities in an arid ecosystem.

The ISME journal pii:10.1038/s41396-020-00803-y [Epub ahead of print].

The overwhelming taxonomic diversity and metabolic complexity of microorganisms can be simplified by a life-history classification; copiotrophs grow faster and rely on resource availability, whereas oligotrophs efficiently exploit resource at the expense of growth rate. Here, we hypothesize that community-level traits inferred from metagenomic data can distinguish copiotrophic and oligotrophic microbial communities. Moreover, we hypothesize that oligotrophic microbial communities harbor more unannotated genes. To test these hypotheses, we conducted metagenomic analyses of soil samples collected from copiotrophic vegetated areas and from oligotrophic bare ground devoid of vegetation in an arid-hyperarid region of the Sonoran Desert, Arizona, USA. Results supported our hypotheses, as we found that multiple ecologically informed life-history traits including average 16S ribosomal RNA gene copy number, codon usage bias in ribosomal genes and predicted maximum growth rate were higher for microbial communities in vegetated than bare soils, and that oligotrophic microbial communities in bare soils harbored a higher proportion of genes that are unavailable in public reference databases. Collectively, our work demonstrates that life-history traits can distill complex microbial communities into ecologically coherent units and highlights that oligotrophic microbial communities serve as a rich source of novel functions.

RevDate: 2020-10-14

Moon K, Kim S, Kang I, et al (2020)

Viral metagenomes of Lake Soyang, the largest freshwater lake in South Korea.

Scientific data, 7(1):349 pii:10.1038/s41597-020-00695-9.

A high number of viral metagenomes have revealed countless genomes of putative bacteriophages that have not yet been identified due to limitations in bacteriophage cultures. However, most virome studies have been focused on marine or gut environments, thereby leaving the viral community structure of freshwater lakes unclear. Because the lakes located around the globe have independent ecosystems with unique characteristics, viral community structures are also distinctive but comparable. Here, we present data on viral metagenomes that were seasonally collected at a depth of 1 m from Lake Soyang, the largest freshwater reservoir in South Korea. Through shotgun metagenome sequencing using the Illumina MiSeq platform, 3.08 to 5.54-Gbps of reads per virome were obtained. To predict the viral genome sequences within Lake Soyang, contigs were constructed and 648 to 1,004 putative viral contigs were obtained per sample. We expect that both viral metagenome reads and viral contigs would contribute in comparing and understanding of viral communities among different freshwater lakes depending on seasonal changes.

RevDate: 2020-10-14

Musengi A, Durrell K, Prins A, et al (2020)

Production and characterisation of a novel actinobacterial DyP-type peroxidase and its application in coupling of phenolic monomers.

Enzyme and microbial technology, 141:109654.

The extracellular peroxidase from Streptomyces albidoflavus BSII#1 was purified to near homogeneity using sequential steps of acid and acetone precipitation, followed by ultrafiltration. The purified peroxidase was characterised and tested for the ability to catalyse coupling reactions between selected phenolic monomer pairs. A 46-fold purification of the peroxidase was achieved, and it was shown to be a 46 kDa haem peroxidase. Unlike other actinobacteria-derived peroxidases, it was only inhibited (27 % inhibition) by relatively high concentrations of sodium azide (5 mM) and was capable of oxidising eleven (2,4-dichlorophenol, 2,6-dimethoxyphenol, 4-tert-butylcatechol, ABTS, caffeic acid, catechol, guaiacol, l-DOPA, o-aminophenol, phenol, pyrogallol) of the seventeen substrates tested. The peroxidase remained stable at temperatures of up to 80 °C for 60 min and retained >50 % activity after 24 h between pH 5.0-9.0, but was most sensitive to incubation with hydrogen peroxide (H2O2; 0.01 mM), l-cysteine (0.02 mM) and ascorbate (0.05 mM) for one hour. It was significantly inhibited by all organic solvents tested (p ≤ 0.05). The Km and Vmax values of the partially purified peroxidase with the substrate 2,4-DCP were 0.95 mM and 0.12 mmol min-1, respectively. The dyes reactive blue 4, reactive black 5, and Azure B, were all decolourised to a certain extent: approximately 30 % decolourisation was observed after 24 h (1 μM dye). The peroxidase successfully catalysed coupling reactions between several phenolic monomer pairs including catechin-caffeic acid, catechin-catechol, catechin-guaiacol and guaiacol-syringaldazine under the non-optimised conditions used in this study. Genome sequencing confirmed the identity of strain BSII#1 as a S. albidoflavus strain. In addition, the genome sequence revealed the presence of one peroxidase gene that includes the twin arginine translocation signal sequence of extracellular proteins. Functional studies confirmed that the peroxidase produced by S. albidoflavus BSII#1 is part of the dye-decolourising peroxidase (DyP-type) family.

RevDate: 2020-10-14

Xing Z, Zhang Y, Li M, et al (2020)

RBUD: A New Functional Potential Analysis Approach for Whole Microbial Genome Shotgun Sequencing.

Microorganisms, 8(10): pii:microorganisms8101563.

Whole metagenome shotgun sequencing is a powerful approach to detect the functional potential of microbial communities. Currently, the read-based metagenomics profiling for established database (RBED) method is one of the two kinds of conventional methods for species and functional annotations. However, the databases, which are established based on test samples or specific reference genomes or protein sequences, limit the coverage of global microbial diversity. The other assembly-based metagenomics profiling for unestablished database (ABUD) method has a low utilization rate of reads, resulting in a lot of biological information loss. In this study, we proposed a new method, read-based metagenomics profiling for unestablished database (RBUD), based on Metagenome Database of Global Microorganisms (MDGM), to solve the above problems. To evaluate the accuracy and effectiveness of our method, the intestinal bacterial composition and function analyses were performed in both avian colibacillosis chicken cases and type 2 diabetes mellitus patients. Comparing to the existing methods, RBUD is superior in detecting proteins, percentage of reads mapping and ontological similarity of intestinal microbes. The results of RBUD are in better agreement with the classical functional studies on these two diseases. RBUD also has the advantages of fast analysis speed and is not limited by the sample size.

RevDate: 2020-10-16

Jakobsen RR, Haahr T, Humaidan P, et al (2020)

Characterization of the Vaginal DNA Virome in Health and Dysbiosis.

Viruses, 12(10): pii:v12101143.

Bacterial vaginosis (BV) is characterized by a reduction in Lactobacillus (L.) spp. abundance and increased abundance of facultative anaerobes, such as Gardnerella spp. BV aetiology is not fully understood; however, bacteriophages could play a pivotal role in the perturbation of the vaginal bacterial community. We investigated the vaginal viral community, including bacteriophages and the association to the bacterial community and BV-status. Vaginal samples from 48 patients undergoing IVF treatment for non-female factor infertility were subjected to metagenomic sequencing of purified virus-like particles. The vaginal viral community was characterized and correlated with the BV-status by Nugent score, bacterial community, structure, and the presence of key vaginal bacterial species. The majority of identified vaginal viruses belonged to the class of double-stranded DNA bacteriophages, with eukaryotic viruses constituting 4% of the total reads. Clear links between the viral community composition and BV (q = 0.006, R = 0.26) as well as the presence of L. crispatus (q = 0.001, R = 0.43), L. iners, Gardnerella spp., and Atopobium vaginae were found (q < 0.002, R > 0.15). The eukaryotic viral community also correlated with BV-status (q = 0.018, R = 0.20). In conclusion, the vaginal virome was clearly linked with bacterial community structure and BV-status.

RevDate: 2020-10-14

Telmadarrehei T, Tang JD, Raji O, et al (2020)

A Study of the Gut Bacterial Community of Reticulitermes virginicus Exposed to Chitosan Treatment.

Insects, 11(10): pii:insects11100681.

A thorough understanding of microbial communities in the gut of lower termites is needed to develop target-specific and environmentally benign wood protection systems. In this study, the bacterial community from Reticulitermes virginicus was examined by Illumina sequencing of 16S ribosomal RNA (rRNA) spanning the V3 and V4 regions. Prior to library preparation, the termites were subjected to five treatments over an 18-day period: three groups were fed on wood treated with 0.5% chitosan, 25% acetic acid, or water, the fourth group was taken directly from the original collection log, and the fifth group was starved. Metagenomic sequences were analyzed using QIIME 2 to understand the treatments' effects on the dynamics of the gut bacteria. Four dominant phyla were detected: Bacteroidetes (34.4% of reads), Firmicutes (20.6%), Elusimicrobia (15.7%), and Proteobacteria (12.9%). A significant effect of chitosan treatment was observed in two phyla; Firmicutes abundance was significantly lower with chitosan treatment when compared to other groups, while Actinobacteria was lower in unexposed and starved termites. The results suggest that chitosan treatment not only affects the structure of the microbial community in the gut, but other treatments such as starving also cause shifts in termite gut communities.

RevDate: 2020-10-16
CmpDate: 2020-10-16

Guo X, Gao Q, Yuan M, et al (2020)

Gene-informed decomposition model predicts lower soil carbon loss due to persistent microbial adaptation to warming.

Nature communications, 11(1):4897 pii:10.1038/s41467-020-18706-z.

Soil microbial respiration is an important source of uncertainty in projecting future climate and carbon (C) cycle feedbacks. However, its feedbacks to climate warming and underlying microbial mechanisms are still poorly understood. Here we show that the temperature sensitivity of soil microbial respiration (Q10) in a temperate grassland ecosystem persistently decreases by 12.0 ± 3.7% across 7 years of warming. Also, the shifts of microbial communities play critical roles in regulating thermal adaptation of soil respiration. Incorporating microbial functional gene abundance data into a microbially-enabled ecosystem model significantly improves the modeling performance of soil microbial respiration by 5-19%, and reduces model parametric uncertainty by 55-71%. In addition, modeling analyses show that the microbial thermal adaptation can lead to considerably less heterotrophic respiration (11.6 ± 7.5%), and hence less soil C loss. If such microbially mediated dampening effects occur generally across different spatial and temporal scales, the potential positive feedback of soil microbial respiration in response to climate warming may be less than previously predicted.

RevDate: 2020-10-15
CmpDate: 2020-10-15

Wang H, Huang J, Wang P, et al (2020)

Insights into the microbiota of larval and postlarval Pacific white shrimp (Penaeus vannamei) along early developmental stages: a case in pond level.

Molecular genetics and genomics : MGG, 295(6):1517-1528.

Increasing studies have revealed strong links among gut microbiota, health status, and shrimp development, but they mainly focus on the microbiota of Pacific white shrimp, Penaeus vannamei, during life stages from juveniles to adults. Little is known about shrimp microbiota dynamics at early developmental stages. In this study, with an aim to profile shrimp microbiota and its dynamics at stages nauplius, zoea, mysis, and early postlarva, we conducted a survey for the successful breeding processes in a commercial hatchery in China, sampled 33 samples including larval/postlarval shrimp, suspended substance in rearing water (SSRW), and nutrition supplements (i.e., algae and brine shrimp larvae) at stages N5, Z2, M2, and P2. The associated bacterial communities were sequenced and comparatively analyzed using high-throughput sequencing of bacterial 16S rRNA genes. Our case study results showed that bacterial community structures and compositions were strikingly different at stages N5, Z2, and P2, indicating the shift of microbiota at the three stages. Many taxa within Gamma-, Alphaproteobacteria, and Flavobacteriia classes were observed to be stage-specifically abundant and identified as taxonomic biomarkers potentially used to differentiate among shrimp at different early developmental stages. Summing up, these results shed light on larval/postlarval microbiota and its dynamics at different early developmental stages, highlighting the potential roles of shrimp development in microbiota formation and shifting.

RevDate: 2020-10-14
CmpDate: 2020-10-14

Tremble K, Suz LM, BTM Dentinger (2020)

Lost in translation: Population genomics and long-read sequencing reveals relaxation of concerted evolution of the ribosomal DNA cistron.

Molecular phylogenetics and evolution, 148:106804.

Concerted evolution of the ribosomal DNA array has been studied in numerous eukaryotic taxa, yet is still poorly understood. rDNA genes are repeated dozens to hundreds of times in the eukaryotic genome (Eickbush and Eickbush, 2007) and it is believed that these arrays are homogenized through concerted evolution (Zimmer et al., 1980; Dover, 1993) preventing the accumulation of intragenomic, and intraspecific, variation. However, numerous studies have reported rampant intragenomic and intraspecific variation in the rDNA array (Ganley and Kobayashi, 2011; Naidoo et al., 2013; Hughes and Petersen, 2001; Lindner and Banik, 2011; Li et al., 2013; Lindner et al., 2013; Hughes et al., 2018), contradicting our current understanding of concerted evolution. The internal transcribed spacers (ITS) of the rDNA cistron are the most commonly used DNA barcoding region in Fungi (Schoch et al., 2012), and rely on concerted evolution to homogenize the rDNA array leading to a "barcode gap" (Puillandre et al., 2012). Here we show that in Boletus edulis Bull., ITS intragenomic variation persists at low allele frequencies throughout the rDNA array, this variation does not correlate with genomic relatedness between populations, and rDNA genes may not evolve in a strictly concerted fashion despite the presence of unequal recombination and gene conversion. Under normal assumptions, heterozygous positions found in ITS sequences represent hybridization between populations, yet through allelic mapping of the rDNA array we found numerous heterozygous alleles to be stochastically introgressed throughout, presenting a dishonest signal of gene flow. Moreover, despite the signal of gene flow in ITS, our organisms were highly inbred, indicating a disconnect between true gene flow and barcoding signals. In addition, we show that while the mechanisms of concerted evolution are ongoing in pseudo-heterozygous individuals, they are not fully homogenizing the ITS array. Concerted evolution of the rDNA array may insufficiently homogenize the ITS gene, allowing for misleading signals of gene flow to persist, vastly complicating the use of the ITS locus for DNA barcoding in Fungi.

RevDate: 2020-10-15
CmpDate: 2020-10-15

Liu Q, Li Y, Song X, et al (2020)

Both gut microbiota and cytokines act to atherosclerosis in ApoE-/- mice.

Microbial pathogenesis, 138:103827.

BACKGROUND: Several studies have suggested a role for the gut microbiome and cytokines in atherosclerosis development, but combined analyses of the changes of the gut microbiota and cytokines have not been explored previously.

METHODS: We treated ApoE-/- and wild-type mice with a high-fat diet for 12 weeks. The gut microbiome and cytokine composition were analyzed using 16S ribosomal DNA sequencing and RayBio Quantibody Arrays, respectively. GO and KEGG analysis were performed to rationalize the potential mechanisms involved in the process of atherosclerosis.

RESULTS: Gut bacterial characteristics in ApoE-/- mice were clearly separated and 21 gut bacterial clades were detected by the LEfSe analysis showing significant differences during the development of atherosclerosis. The relative abundance of Verrucomicrobia, Bacteroidaceae, Bacteroides, and Akkermansia showed significant positive correlations with serum total cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL). Additionally, the relative abundance of Ruminococcaceae was positive with the level of HDL and the abundance of Rikenellaceae showed a negative relationship with the level of TG and LDL. Thirteen differentially expressed proteins were identified with P-value < 0.05. CXCL5, FGF2, and E-Selectin were significantly negatively associated with Akkermansia and Verrucomicrobia. Additionally, CXCL5 was significantly negatively correlated with Bacteroides and Bacteroidaceae. Three "cellular component" subcategories, 24 ″molecular function" subcategories, 752 ″biological process" subcategories and 29 statistically remarkable KEGG pathway categories were identified.

CONCLUSIONS: Gut microbiota changes of the mice having atherosclerosis and their relationship with the inflammatory status could be one of the major etiological mechanisms underlying atherosclerosis.

RevDate: 2020-10-15
CmpDate: 2020-10-15

Khan KA, Al-Ghamdi AA, Ghramh HA, et al (2020)

Structural diversity and functional variability of gut microbial communities associated with honey bees.

Microbial pathogenesis, 138:103793.

Microbial consortia accompanied to all eukaryotes can be inherited from ancestors, environment, and/or from various food source. Gut microbiota study is an emerging discipline of biological sciences that expands our understanding of the ecological and functional dynamics of gut environments. Microorganisms associated with honey bees play an important role in food digestion, colony performance, immunity, pollination, antagonistic effect against different pathogens, amelioration of food and many more. Although, many repots about honey bee gut microbiota are well documented, microbiome with other key components of honey bees such as larvae, adults, their food (pollen, beebread, and honey), honey combs, and floral nectar are poorly understood. Mutual interactions and extent of the roles of microbial communities associated with honey bees are still unclear and demand for more research on the nutritional physiology and health benefits of this ecologically and economically important group. Here in this study, we highlighted all the honey bee microbiome that harbored from different life stages and other relevant components. The anatomical parts of honey bee (larvae, adults), food source (pollen, beebread, and honey), honey combs, and floral nectar were highly flourished by numerous microorganisms like bacteria (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Actinobacteria, Actinomycetes, Bacilli, Bacteroidetes, Cocci, Clostridia, Coliforms, Firmicutes, Flavobacteriia, Mollicutes) and fungi (Dothideomycetes, Eurotiomycetes, Mucormycotina, Saccharomycetes, Zygomycetes, Yeasts, Molds). Some distinctive microbial communities of a taxonomically constrained species have coevolved with social bees. This contribution is to enhance the understanding of honey bee gut microbiota, to accelerate bee microbiota and microbiome research in general and to aid design of future experiments in this growing field.

RevDate: 2020-10-13

Zhang T, Yin Q, Shi Y, et al (2020)

Microbial physiology and interactions in anammox systems with the intermittent addition of organic carbons.

Bioresource technology, 319:124226 pii:S0960-8524(20)31500-5 [Epub ahead of print].

Organic carbon can affect nitrogen removal in the anaerobic ammonia oxidation (anammox) process. Two continuous up-flow anaerobic sludge blanket (UASB) reactors were operated under autotrophic (UASBN, without organic carbon) and mixotrophic (UASBCN, with the intermittent addition of acetate and propionate) conditions. Stable operation of anammox systems was achieved, with the nitrogen removal rate and percentage of 2.12 g/(L·d) and 86.4% in UASBN, and 2.09 g/(L·d) and 85.0% in UASBCN, respectively. The network of Candidatus Kuenenia, Thauera, and Nitrosomanas contributed to both nitrogen and carbon metabolisms, and the intermittent addition of acetate and propionate strengthened Ca. Kuenenia's ability to utilize several types of carbon sources. Anammox bacteria showed activity in the presence of organic carbon and without inorganic carbon, confirming the mixotrophic characteristic of Ca. Kuenenia. Cross-feeding of amino acids and vitamins existed among functional microorganisms, with extracellular polymeric substances acting as the media for microbial interactions.

RevDate: 2020-10-13

Zhang Z, Qin F, Chen F, et al (2020)

Culturing novel and abundant pelagiphages in the ocean.

Environmental microbiology [Epub ahead of print].

Viruses play a key role in biogeochemical cycling and host mortality, metabolism, physiology and evolution in the ocean. Viruses that infect the globally abundant SAR11 bacteria (pelagiphages) were reported to be an important component of the marine viral communities. Our current knowledge of pelagiphages is based on a few studies and therefore is limited. In this study, 10 new pelagiphages were isolated and genomically characterized. These pelagiphages represent the first cultivated representatives of four viral lineages only found in metagenomic sequencing datasets previously. Many abundant environmental viral sequences i.e. single-virus vSAG 37-F6 and several Global Ocean Viromes (GOV) viral populations, are now further confirmed with these pelagiphages. Viromic read mapping reveals that these new pelagiphages are globally distributed in the ocean and can be detected throughout the water column. Remarkably, isolation of these pelagiphages contributed up to 12% of all viromic reads annotated in the analyzed viromes. Altogether, this study has greatly broadened our understanding of pelagiphages regarding their morphology, genetic diversity, infection strategies, and distribution pattern. The availability of these newly isolated pelagiphages and their genome sequences will allow us to further explore their infectivities and ecological strategies. This article is protected by copyright. All rights reserved.


RJR Experience and Expertise


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.


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.


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.


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.


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.


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.


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.


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.

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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

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Curriculum Vitae for R J Robbins

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