Andean Wetlands: a hotspot of extremophile microbial communities associated with Microbial Evaporites, Microbialites and Stromatolites.

FARIAS MARIA EUGENIA

Simposio; ISME; 2012

ecosystem of shallow lakes at altitudes from 3,000 to 5,000 m. Although exposed to extreme conditions (high UV irradiation, hypersalinity, drastic temperature changes, desiccation, high pH, high As content, low O2 pressure, etc.), an outstanding microbial biodiversity has developed, in most ecotypes mainly associated with minerals such as microbialites and microbial films associated with evaporites. In this study we provide a detailed description of diverse Andean microbialites forming atthe shore of a High-Altitude Lakes located at both sides of the Andean. Physico-chemical characteristics of the environment, mineralogy of the abiotic solid phase, bacterial diversity (based on 16S rDNA by pirosequencing and scanning electronic imagines), and some aspects of microbial activity and physiology like A vertical microprofile of physicochemical parameters and hyperspectral imaging of major pigments distribution are presented. The studied environments included: i) Stromatolites from Socompa Lake at 3800 m above sea level (m a.s.l.) at the north-west of Argentina in the Andean plateau (pH 8 conductivity 180 mS and 32 mgL-1 As). ii) Endolitic biofilms associated to Gaylussite precipitation at Laguna Diamante placed inside Volcano Galan caldera at 4750 m a.s.l. (pH 10, conductivity 213 mS and As 212 mg.L-1 ). iii) Endolithic communities in evaporite deposits at Ojos de Mar de Tolar Grande at 3600 m asl (pH6 conductivity 190 mS). iv) Microbial mats, stromatolites and endolithic communities in evaporite deposits at lagunas Tebenquiche and Brava placed at Salar de Atacama Chile at 2000 m a.s.l.; where a succession of microbial ecosystems, that that goes from microbial mats, aragonite stromatolites to endolithic communities associated to gypsum evaporites can be found in these lakes. All the reported ecosystems, are developing under one of the most extreme conditions reported on Earth, in a very similar setting of that of Ancient Earth, the opportunity to gain insight into the past is now presented as well as to provide critical information for the search for life on other planets.