Acidophilic microbial communities from the Copahue Geothermal system. Rio Agrio as an environmental gradient model system

GIAVENO M. A

La serena

Congreso; XXXIX Congreso Chileno de Microbiologia; 2017

Sociedad de Microbiologia de Chile

Acidophilic microbial communities from the Copahue Geothermal System. Rio Agrio as an environmental gradient model systemGiaveno, M1., 1Quimica , Ingeniería, Universidad Nacional del comahue.The geothermal system Copahue?Caviahue is located, in the Argentinian province of Neuquen. The Copahue Volcano is a stratovolcano with an acidic crater lake (pH 0.2?1.1) that feeds four hot springs spanning both Argentinian and Chilean territory. They exhibit wide ranges of pH (1-7) and temperature (20-90°C) and are colonized by diverse extremophilic life forms. The main water drainage in the system is Rio Agrio, which starts as a hot spring (pH 0.3?2.3) and gets cooled and diluted with tributary inflows farther downstream. This river discharges its waters in the Lake Caviahue (pH 2.1?3.7) also acidic. The overflows waters give origin to the Lower Rio Agrio (pH 2.1?6.0) which flows down till the Rio Ñorquin where it gets further diluted. Thanks to the input of hydrothermal waters, the pH and the temperature gradually vary downstream, from 70°C and pH 0.5 near the source, to 14°C and pH=7 when joining the Rio Ñorquin. These changes in physicochemical parameters make of Río Agrio a unique and extremely interesting natural environment for studying extremophilic microorganisms and their interactions with the habitat. For these and other reasons, Rio Agrio emerges as an environmental gradient model system in Latin America.Since 1997 our research group has studied the biodiversity and ecology of acidophilic microorganisms from this geothermal system andexplored their biotechnological potential. Microbiological studies performed have focused on the characterisation and isolation of native acidophilic microorganismsby means of culture dependent and independent techniques setting the basis for deeper eco-evolutionary studies. Thebiodiversity detected at Río Agrio is higher than that of other acidic natural rivers or volcanic habitats analysed thus far, but lower than that presented on acidic mine drainage effluents making this system a highly tractable and appealing model system for community and population resolved studies.These pioneering molecular studies have paved the way for focused studies on the acidophilic prokaryotic communities composition and interactions, in the context of landscape ecology. As well, biological novelty uncovered in this unique environment is like to help improve or develop new biotechnological processes relevant for bioleaching and heavy metal bioremediation.This work was partially supported by grants PIP 0348 (CONICET), PICT-2010-0749 (ANPCYT) and Universidad Nacional del Comahue