Unraveling stress resistance from metagenomic sequence of Socompa stromatolites

KURTH D.; ALBARRACÍN V.H.; REVALE S.; RASCOVAN, N.; TIMMERMAN B.; VAZQUEZ M.P.; FARIAS M.E.

Jena

Conferencia; GCB 2012 GERMAN CONFERENCE ON BIOINFORMATICS 2012; 2012

High Altitude Andean Lakes (HAAL) are extreme environments exposed to high ultraviolet radiation (UVR), elevated salinity, and high concentration of arsenic, located in northwestern Argentina 3500 meters above sea level. Living stromatolites were recently identified by our group in one of these lakes, Laguna Socompa [AD11]. These ancient microbial communities and its location in these extreme environments are key to understand microbial processes related to early life on Earth, and the possibility of life in Mars. In this work a metagenomic approach was applied to study Socompa stromatolites. Environmental sequencing of total DNA obtained from Socompa stromatolites allowed a phylogenetic characterization and functional analysis of the community. Further analysis of metagenomic sequences allowed the identification of genes related to two processes of outmost importance for the survival of bacteria in the HAAL: resistance to UV radiation and arsenic tolerance. High UV irradiation on these extreme environments enhances the selection of systems to withstand this radiation. It can be expected that the HAAL photolyases have unique properties allowing maximum activity and improved resistance to UV [AP12]. Analysis of genes related to arsenic resistance showed the presence of unusual extrusion pumps. These are only isolated examples of the rich genetic biodiversity found in these harsh habitats. Further studies will reveal new genes with interesting biotechnological applications such as production of metabolites with potential therapeutic effects, as antibiotics, or UV resistant compounds