scholarly journals The global-scale distributions of soil protists and their contributions to belowground systems

2020 ◽  
Vol 6 (4) ◽  
pp. eaax8787 ◽  
Author(s):  
Angela M. Oliverio ◽  
Stefan Geisen ◽  
Manuel Delgado-Baquerizo ◽  
Fernando T. Maestre ◽  
Benjamin L. Turner ◽  
...  

Protists are ubiquitous in soil, where they are key contributors to nutrient cycling and energy transfer. However, protists have received far less attention than other components of the soil microbiome. We used amplicon sequencing of soils from 180 locations across six continents to investigate the ecological preferences of protists and their functional contributions to belowground systems. We complemented these analyses with shotgun metagenomic sequencing of 46 soils to validate the identities of the more abundant protist lineages. We found that most soils are dominated by consumers, although parasites and phototrophs are particularly abundant in tropical and arid ecosystems, respectively. The best predictors of protist composition (primarily annual precipitation) are fundamentally distinct from those shaping bacterial and archaeal communities (namely, soil pH). Some protists and bacteria co-occur globally, highlighting the potential importance of these largely undescribed belowground interactions. Together, this study allowed us to identify the most abundant and ubiquitous protists living in soil, with our work providing a cross-ecosystem perspective on the factors structuring soil protist communities and their likely contributions to soil functioning.

2019 ◽  
Vol 23 (2) ◽  
pp. 137-148 ◽  
Author(s):  
Alaa E. Rabee ◽  
Robert J. Forster ◽  
Chijioke O. Elekwachi ◽  
Khaled Z. Kewan ◽  
Ebrahim Sabra ◽  
...  

2019 ◽  
Author(s):  
Andrew Oliver ◽  
Brandon LaMere ◽  
Claudia Weihe ◽  
Stephen Wandro ◽  
Karen L. Lindsay ◽  
...  

AbstractBackgroundMicrobes and their metabolic products influence early-life immune and microbiome development, yet remain understudied during pregnancy. Vaginal microbial communities are typically dominated by one or a few well adapted microbes, which are able to survive in a narrow pH range. In comparison to other human-associated microbes, vaginal microbes are adapted to live on host-derived carbon sources, likely sourced from glycogen and mucin present in the vaginal environment.MethodsUsing 16S rRNA and ITS amplicon sequencing, we characterized the cervicovaginal microbiomes of 18 healthy women throughout the three trimesters of pregnancy. Shotgun metagenomic sequencing permitted refinement of the taxonomy established by amplicon sequencing, and identification of functional genes. Additionally, we analyzed saliva and urine metabolomes using GC-TOF and LC-MS/MS lipidomics approaches for samples from mothers and their infants through the first year of life.ResultsAmplicon sequencing revealed most women had either a simple community with one highly abundant species of Lactobacillus or a more diverse community characterized by a high abundance of Gardnerella, as has also been previously described in several independent cohorts. Integrating GC-TOF and lipidomics data with amplicon sequencing, we found metabolites that distinctly associate with particular communities. For example, cervicovaginal microbial communities dominated by Lactobacillus crispatus also have high mannitol levels, which contradicts the basic characterization of L. crispatus as a homofermentative Lactobacillus species. It may be that fluctuations in which Lactobacillus dominate a particular vaginal microbiome are dictated by the availability of host sugars, such as fructose, which is the most likely substrate being converted to mannitol. Furthermore, indole-3-lactate (ILA) was also indicative of L. crispatus specifically. ILA has immunomodulatory properties through binding the human aryl hydrocarbon receptor (AhR), which may maintain the especially low diversity of L. crispatus dominated communities.ConclusionsOverall, using a multi-‘omic approach, we begin to address the genetic and molecular means by which a particular vaginal microbiome becomes vulnerable to large changes in composition.


2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Xiaofang Li ◽  
M. Mominul Islam ◽  
Liang Chen ◽  
Likun Wang ◽  
Xin Zheng

ABSTRACT Metallothionein (MT) genes are valuable genetic materials for developing metal bioremediation tools. Currently, a limited number of prokaryotic MTs have been experimentally identified, which necessitates the expansion of bacterial MT diversity. In this study, we conducted a metagenomics-guided analysis for the discovery of potential bacterial MT genes from the soil microbiome. More specifically, we combined resistance gene enrichment through diversity loss, metagenomic mining with a dedicated MT database, evolutionary trace analysis, DNA chemical synthesis, and functional genomic validation to identify novel MTs. Results showed that Cu stress induced a compositional change in the soil microbiome, with an enrichment of metal-resistant bacteria in soils with higher Cu concentrations. Shotgun metagenomic sequencing was performed to obtain the gene pool of environmental DNA (eDNA), which was subjected to a local BLAST search against an MT database for detecting putative MT genes. Evolutional trace analysis led to the identification of 27 potential MTs with conserved cysteine/histidine motifs different from those of known prokaryotic MTs. Following chemical synthesis of these 27 potential MT genes and heterologous expression in Escherichia coli, six of them were found to improve the hosts’ growth substantially and enhanced the hosts’ sorption of Cu, Cd, and Zn, among which MT5 led to a 13.7-fold increase in Cd accumulation. Furthermore, four of them restored Cu and/or Cd resistance in two metal-sensitive E. coli strains. IMPORTANCE The metagenomics-guided procedure developed here bypasses the difficulties encountered in classic PCR-based approaches and led to the discovery of novel MT genes, which may be useful in developing bioremediation tools. The procedure used here expands our knowledge on the diversity of bacterial MTs in the environment and may also be applicable to identify other functional genes from eDNA.


2020 ◽  
Vol 6 (3) ◽  
Author(s):  
Catarina I. Mendes ◽  
Erley Lizarazo ◽  
Miguel P. Machado ◽  
Diogo N. Silva ◽  
Adriana Tami ◽  
...  

Dengue virus (DENV) represents a public health threat and economic burden in affected countries. The availability of genomic data is key to understanding viral evolution and dynamics, supporting improved control strategies. Currently, the use of high-throughput sequencing (HTS) technologies, which can be applied both directly to patient samples (shotgun metagenomics) and to PCR-amplified viral sequences (amplicon sequencing), is potentially the most informative approach to monitor viral dissemination and genetic diversity by providing, in a single methodological step, identification and characterization of the whole viral genome at the nucleotide level. Despite many advantages, these technologies require bioinformatics expertise and appropriate infrastructure for the analysis and interpretation of the resulting data. In addition, the many software solutions available can hamper the reproducibility and comparison of results. Here we present DEN-IM, a one-stop, user-friendly, containerized and reproducible workflow for the analysis of DENV short-read sequencing data from both amplicon and shotgun metagenomics approaches. It is able to infer the DENV coding sequence (CDS), identify the serotype and genotype, and generate a phylogenetic tree. It can easily be run on any UNIX-like system, from local machines to high-performance computing clusters, performing a comprehensive analysis without the requirement for extensive bioinformatics expertise. Using DEN-IM, we successfully analysed two types of DENV datasets. The first comprised 25 shotgun metagenomic sequencing samples from patients with variable serotypes and genotypes, including an in vitro spiked sample containing the four known serotypes. The second consisted of 106 paired-end and 76 single-end amplicon sequences of DENV 3 genotype III and DENV 1 genotype I, respectively, where DEN-IM allowed detection of the intra-genotype diversity. The DEN-IM workflow, parameters and execution configuration files, and documentation are freely available at https://github.com/B-UMMI/DEN-IM).


2019 ◽  
Author(s):  
Xinxing Liu ◽  
Yong-Hong Wu ◽  
Xi Liu ◽  
Wu Han-yan ◽  
Jianping Xie ◽  
...  

AbstractRecycling effluent has become a bottleneck and an environmental risk associated with the regular production of bauxite via flotation and the sustainable development of the aluminum industry in China. To find a practical direction for biotreatment, the bacterial and archaeal communities in recycling effluents containing concentrate and tailings from bauxite flotation plants were investigated by a metagenomic sequencing method in association with the evaluated geochemical properties. The results showed that Paracoccus, Desulfomicrobium, Exiguobacterium, Tindallia, Ercella and Anoxynatronum were the primary bacterial genera and Methanothrix, Methanobacterium, Nitrososphaera and Methanosarcina were the dominant archaeal genera. Upon combining the microbial diversity and the geochemical properties of the two sample types, the microbial community containing Desulfomicrobium, Paracoccus, Tindallia, Methanobacterium, Methanothrix and Nitrososphaera was better adapted to the biodegradation of flotation collectors, and the microbial community consisting of Paracoccus, Exiguobacterium, Methanothrix and Methanobacterium was more efficient at hydrolyzed polyacrylamide (HPAM) biodegradation. In addition, a large proportion of unclassified OTUs has indicated that recycling effluent is a worthy resource for isolating new strains from the Firmicutes phylum.


2021 ◽  
Vol 9 (4) ◽  
pp. 707
Author(s):  
J. Christopher Noone ◽  
Fabienne Antunes Ferreira ◽  
Hege Vangstein Aamot

Our culture-independent nanopore shotgun metagenomic sequencing protocol on biopsies has the potential for same-day diagnostics of orthopaedic implant-associated infections (OIAI). As OIAI are frequently caused by Staphylococcus aureus, we included S. aureus genotyping and virulence gene detection to exploit the protocol to its fullest. The aim was to evaluate S. aureus genotyping, virulence and antimicrobial resistance genes detection using the shotgun metagenomic sequencing protocol. This proof of concept study included six patients with S. aureus-associated OIAI at Akershus University Hospital, Norway. Five tissue biopsies from each patient were divided in two: (1) conventional microbiological diagnostics and genotyping, and whole genome sequencing (WGS) of S. aureus isolates; (2) shotgun metagenomic sequencing of DNA from the biopsies. Consensus sequences were analysed using spaTyper, MLST, VirulenceFinder, and ResFinder from the Center for Genomic Epidemiology (CGE). MLST was also compared using krocus. All spa-types, one CGE and four krocus MLST results matched Sanger sequencing results. Virulence gene detection matched between WGS and shotgun metagenomic sequencing. ResFinder results corresponded to resistance phenotype. S. aureus spa-typing, and identification of virulence and antimicrobial resistance genes are possible using our shotgun metagenomics protocol. MLST requires further optimization. The protocol has potential application to other species and infection types.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1041
Author(s):  
Rita Mormando ◽  
Alan J. Wolfe ◽  
Catherine Putonti

Polyomaviruses are abundant in the human body. The polyomaviruses JC virus (JCPyV) and BK virus (BKPyV) are common viruses in the human urinary tract. Prior studies have estimated that JCPyV infects between 20 and 80% of adults and that BKPyV infects between 65 and 90% of individuals by age 10. However, these two viruses encode for the same six genes and share 75% nucleotide sequence identity across their genomes. While prior urinary virome studies have repeatedly reported the presence of JCPyV, we were interested in seeing how JCPyV prevalence compares to BKPyV. We retrieved all publicly available shotgun metagenomic sequencing reads from urinary microbiome and virome studies (n = 165). While one third of the data sets produced hits to JCPyV, upon further investigation were we able to determine that the majority of these were in fact BKPyV. This distinction was made by specifically mining for JCPyV and BKPyV and considering uniform coverage across the genome. This approach provides confidence in taxon calls, even between closely related viruses with significant sequence similarity.


Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Yusuke Okazaki ◽  
Shohei Fujinaga ◽  
Michaela M. Salcher ◽  
Cristiana Callieri ◽  
Atsushi Tanaka ◽  
...  

Abstract Background Freshwater ecosystems are inhabited by members of cosmopolitan bacterioplankton lineages despite the disconnected nature of these habitats. The lineages are delineated based on > 97% 16S rRNA gene sequence similarity, but their intra-lineage microdiversity and phylogeography, which are key to understanding the eco-evolutional processes behind their ubiquity, remain unresolved. Here, we applied long-read amplicon sequencing targeting nearly full-length 16S rRNA genes and the adjacent ribosomal internal transcribed spacer sequences to reveal the intra-lineage diversities of pelagic bacterioplankton assemblages in 11 deep freshwater lakes in Japan and Europe. Results Our single nucleotide-resolved analysis, which was validated using shotgun metagenomic sequencing, uncovered 7–101 amplicon sequence variants for each of the 11 predominant bacterial lineages and demonstrated sympatric, allopatric, and temporal microdiversities that could not be resolved through conventional approaches. Clusters of samples with similar intra-lineage population compositions were identified, which consistently supported genetic isolation between Japan and Europe. At a regional scale (up to hundreds of kilometers), dispersal between lakes was unlikely to be a limiting factor, and environmental factors or genetic drift were potential determinants of population composition. The extent of microdiversification varied among lineages, suggesting that highly diversified lineages (e.g., Iluma-A2 and acI-A1) achieve their ubiquity by containing a consortium of genotypes specific to each habitat, while less diversified lineages (e.g., CL500-11) may be ubiquitous due to a small number of widespread genotypes. The lowest extent of intra-lineage diversification was observed among the dominant hypolimnion-specific lineage (CL500-11), suggesting that their dispersal among lakes is not limited despite the hypolimnion being a more isolated habitat than the epilimnion. Conclusions Our novel approach complemented the limited resolution of short-read amplicon sequencing and limited sensitivity of the metagenome assembly-based approach, and highlighted the complex ecological processes underlying the ubiquity of freshwater bacterioplankton lineages. To fully exploit the performance of the method, its relatively low read throughput is the major bottleneck to be overcome in the future.


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