FreshOmics: A manually curated and standardized -omics database for investigating freshwater microbiomes.

Freshwater is a critical resource for human survival but severely threatened by anthropogenic activities and climate change. These changes strongly impact the abundance and diversity of the microbial communities which are key players in the functioning of these aquatic ecosystems. Although widely documented since the emergence of high-throughput sequencing approaches, the information on these natural microbial communities is scattered among thousands of publications and it is therefore difficult to investigate the temporal dynamics and the spatial distribution of microbial taxa within or across ecosystems.

Diversity and Dynamics of Active Small Microbial Eukaryotes in the Anoxic Zone of a Freshwater Meromictic Lake (Pavin, France).

Microbial eukaryotes play a crucial role in ecosystem functioning and oxygen is considered to be one of the strongest barriers against their local dispersal. However, diversity of microbial eukaryotes in freshwater habitats with oxygen gradients has previously received very little attention. We applied high-throughput sequencing (V4 region of the 18S rRNA gene) in conjunction with quantitative PCR (DNA and RNA) and fluorescent in situ hybridization (FISH) analyses, to provide an unique spatio-temporal analysis of microbial eukaryotes diversity and potential activity in a meromictic freshwater lake (lake Pavin).

Analysis of metagenomic data reveals common features of halophilic viral communities across continents.

Microbial communities from hypersaline ponds, dominated by halophilic archaea, are considered specific of such extreme conditions. The associated viral communities have accordingly been shown to display specific features, such as similar morphologies among different sites. However, little is known about the genetic diversity of these halophilic viral communities across the Earth.

Temporal dynamics and phylogenetic diversity of free-living and particle-associated Verrucomicrobia communities in relation to environmental variables in a mesotrophic lake.

In the present study, the abundance and phylogenetic diversity of free-living and particle-associated Verrucomicrobia were investigated in a mesotrophic lake by quantitative PCR and sequencing of the 16S rRNA gene. The relative verrucomicrobial 16S rRNA gene abundance accounted for 0.02% to 1.