Unraveling stress resistance from metagenomic sequence of Socompa stromatolites

KURTH, D; ALBARRACIN, V; REVALE, S; RASCOVAN, N.; TIMMERMANN, B; VAZQUEZ, M; FARIAS, ME

Jena

Congreso; German Conference on Bioinformatics 2012; 2012

Jena Center for Bioinformatics (JCB)

High Altitude Andean Lakes (HAAL) are extreme environments exposed to high ultravioletradiation (UVR), elevated salinity, and high concentration of arsenic, located innorthwestern Argentina 3500 meters above sea level. Living stromatolites were recentlyidentified by our group in one of these lakes, Laguna Socompa [AD11]. These ancientmicrobial communities and its location in these extreme environments are key to understandmicrobial 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 aphylogenetic characterization and functional analysis of the community. Further analysis ofmetagenomic sequences allowed the identification of genes related to two processes ofoutmost importance for the survival of bacteria in the HAAL: resistance to UV radiation andarsenic tolerance. High UV irradiation on these extreme environments enhances theselection of systems to withstand this radiation. It can be expected that the HAALphotolyases have unique properties allowing maximum activity and improved resistance toUV [AP12]. Analysis of genes related to arsenic resistance showed the presence of unusualextrusion pumps.These are only isolated examples of the rich genetic biodiversity found in these harshhabitats. Further studies will reveal new genes with interesting biotechnological applicationssuch as production of metabolites with potential therapeutic effects, as antibiotics, or UVresistant compounds.References[AD11] Albarracín, V.H., J.R. Dib, et al. A harsh life of indigenous proteobacteria at theandean mountains: Microbial diversity and resistance mechanisms towards extremeconditions. In Proteobacteria: Phylogeny, metabolic diversity and ecologicaleffects. M. L. Sezenna, Nova Publishers, 2011.[AP12] Albarracín, V.H., G.P. Pathak, et al. Extremophilic Acinetobacter Strains fromHigh-Altitude Lakes in Argentinean Puna: Remarkable UV-B Resistance andEfficient DNA Damage Repair. Orig Life Evol Biosph 42(2-3): 201-221, 2012.