Dataset Information

Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow.

ABSTRACT: The diversity of bacteria present in surface snow around four Russian stations in Eastern Antarctica was studied by high throughput sequencing of amplified 16S rRNA gene fragments and shotgun metagenomic sequencing. Considerable class- and genus-level variation between the samples was revealed indicating a presence of inter-site diversity of bacteria in Antarctic snow. Flavobacterium was a major genus in one sampling site and was also detected in other sites. The diversity of flavobacterial type II-C CRISPR spacers in the samples was investigated by metagenome sequencing. Thousands of unique spacers were revealed with less than 35% overlap between the sampling sites, indicating an enormous natural variety of flavobacterial CRISPR spacers and, by extension, high level of adaptive activity of the corresponding CRISPR-Cas system. None of the spacers matched known spacers of flavobacterial isolates from the Northern hemisphere. Moreover, the percentage of spacers with matches with Antarctic metagenomic sequences obtained in this work was significantly higher than with sequences from much larger publically available environmental metagenomic database. The results indicate that despite the overall very high level of diversity, Antarctic Flavobacteria comprise a separate pool that experiences pressures from mobile genetic elements different from those present in other parts of the world. The results also establish analysis of metagenomic CRISPR spacer content as a powerful tool to study bacterial populations diversity.

SUBMITTER: Lopatina A

PROVIDER: S-EPMC4814470 | biostudies-literature | 2016

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow.

Lopatina Anna A Medvedeva Sofia S Shmakov Sergey S Logacheva Maria D MD Krylenkov Vjacheslav V Severinov Konstantin K

Frontiers in microbiology 20160331

The diversity of bacteria present in surface snow around four Russian stations in Eastern Antarctica was studied by high throughput sequencing of amplified 16S rRNA gene fragments and shotgun metagenomic sequencing. Considerable class- and genus-level variation between the samples was revealed indicating a presence of inter-site diversity of bacteria in Antarctic snow. Flavobacterium was a major genus in one sampling site and was also detected in other sites. The diversity of flavobacterial type ...[more]

PMID: 27064693

Similar Datasets

Project description:Soil microbial diversity represents the largest global reservoir of novel microorganisms and enzymes. In this study, we coupled functional metagenomics and DNA stable-isotope probing (DNA-SIP) using multiple plant-derived carbon substrates and diverse soils to characterize active soil bacterial communities and their glycoside hydrolase genes, which have value for industrial applications. We incubated samples from three disparate Canadian soils (tundra, temperate rainforest, and agricultural) with five native carbon ((12)C) or stable-isotope-labeled ((13)C) carbohydrates (glucose, cellobiose, xylose, arabinose, and cellulose). Indicator species analysis revealed high specificity and fidelity for many uncultured and unclassified bacterial taxa in the heavy DNA for all soils and substrates. Among characterized taxa, Actinomycetales (Salinibacterium), Rhizobiales (Devosia), Rhodospirillales (Telmatospirillum), and Caulobacterales (Phenylobacterium and Asticcacaulis) were bacterial indicator species for the heavy substrates and soils tested. Both Actinomycetales and Caulobacterales (Phenylobacterium) were associated with metabolism of cellulose, and Alphaproteobacteria were associated with the metabolism of arabinose; members of the order Rhizobiales were strongly associated with the metabolism of xylose. Annotated metagenomic data suggested diverse glycoside hydrolase gene representation within the pooled heavy DNA. By screening 2,876 cloned fragments derived from the (13)C-labeled DNA isolated from soils incubated with cellulose, we demonstrate the power of combining DNA-SIP, multiple-displacement amplification (MDA), and functional metagenomics by efficiently isolating multiple clones with activity on carboxymethyl cellulose and fluorogenic proxy substrates for carbohydrate-active enzymes. Importance: The ability to identify genes based on function, instead of sequence homology, allows the discovery of genes that would not be identified through sequence alone. This is arguably the most powerful application of metagenomics for the recovery of novel genes and a natural partner of the stable-isotope-probing approach for targeting active-yet-uncultured microorganisms. We expanded on previous efforts to combine stable-isotope probing and metagenomics, enriching microorganisms from multiple soils that were active in degrading plant-derived carbohydrates, followed by construction of a cellulose-based metagenomic library and recovery of glycoside hydrolases through functional metagenomics. The major advance of our study was the discovery of active-yet-uncultivated soil microorganisms and enrichment of their glycoside hydrolases. We recovered positive cosmid clones in a higher frequency than would be expected with direct metagenomic analysis of soil DNA. This study has generated an invaluable metagenomic resource that future research will exploit for genetic and enzymatic potential.

Project description:Marine sponges host dense, diverse, and species-specific microbial communities around the globe; however, most of the current knowledge is restricted to species from tropical and temperate waters. Only recently, some studies have assessed the microbiome of a few Antarctic sponges; however, contrary to low mid-latitude sponges, the knowledge about temporal (stability) patterns in the bacterial communities of Antarctic sponges is absent. Here, we studied the temporal patterns of bacterial communities in the Antarctic sponges Mycale (Oxymycale) acerata, Isodictya sp., Hymeniacidon torquata, and Tedania (Tedaniopsis) wellsae that were tagged in situ and monitored during three austral summers over a 24-month period. By using amplicon sequencing of the bacterial 16S rRNA gene we found that the microbiome differed between species. In general, bacterial communities were dominated by gammaproteobacterial OTUs; however, M. acerata showed the most distinct pattern, being dominated by a single betaproteobacterial OTU. The analysis at OTU level (defined at 97% sequence similarity) showed a highly stable bacterial community through time, despite the abnormal seawater temperatures (reaching 3°C) and rates of temperature increase of 0.15°C day-1 recorded in austral summer 2017. Sponges were characterized by a small core bacterial community that accounted for a high percentage of the abundance. Overall, no consistent changes in core OTU abundance were recorded for all studied species, confirming a high temporal stability of the microbiome. In addition, predicted functional pathway profiles showed that the most abundant pathways among all sponges belonged mostly to metabolism pathway groups (e.g., amino acid, carbohydrate, energy, and nucleotide). The predicted functional pathway patterns differed among the four sponge species. However, no clear temporal differences were detected supporting what was found in terms of the relatively stable composition of the bacterial communities.

Dataset Information

Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow.

Publications

Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets