Ancient saltern metagenomics: tracking changes in microbes and their viruses from the underground to the surface

Microbial communities in hypersaline underground waters derive from ancient organisms trapped within the evaporitic salt crystals and are part of poorly known subterranean biosphere. Here, we characterized viral prokaryotic assemblages present springs that dissolve Triassic-Keuper evaporite rocks feed Añana Salt Valley (Araba/Alava, Basque Country, Spain). Four water samples (around 23% total salinity) with different levels exposure to open air were analysed by means microscopy metagenomics. Cells viruses spring had lower concentrations than what normally found environments seemed be mostly inactive. Upon air, there was an increase activity both cells as well a selection phylotypes. The inhabited rich community harbouring diverse set genes coding for retinal binding proteins. A 35 contigs 15 104 kb, representing partial or genomes, assembled their evolutionary changes through system followed SNP analysis metagenomic island tracking. Overall, changed quickly upon conditions.