Microbial biodiversity in the Copahue geothermal region, an extreme environment dominated by an active volcano in Cordillera de los Andes

DONATI E.R.; URBIETA, M. S.

Clement Town, Dehradun, Uttarakhand, India

Conferencia; Mountain ecosystems: Biodiversity and adaptations under Climate Change scenario; 2023

Graphic Era Deemed to be University

The Copahue geothermal area is located on the Northwest of Neuquén province in Patagonia, Argentina, on the Cordillera de los Andes, one of the world’s most important mountain systems. This naturally acidic extreme environment is dominated by the still active Copahue volcano, a stratovolcano of approx. 2965 m.a.sl., whose cyclic eruptive periods shape the landscape and the geo-physicochemical characteristics of the place. Due to its location and particular geology the area is rich in sulphur and sulphur minerals as well as different compounds of iron. The Copahue geothermal area, of approx. 250 Km2, has two different parts: the Copahue volcano-Río Agrio system and the geothermal ponds. Río Agrio is a natural acidic river that originates at two geothermal ponds a few meters below the volcano crater and runs down its hill maintaining the low pH values for almost its entire path, despite receiving many tributary neutral water courses. Such stability is in part due to the metabolic activity of the many acidophilic, sulphur and/or iron oxidising chemolitoautotrophic microbial species that colonise its water and sediments. On the other hand, the geothermal manifestations, pools, ponds and hot springs with a wide range of temperature and pH, are a constantly changing environment, highly dependent on the volcanic activity. In general, the acidic ponds are also dominated by acidophilic chemolitoautotrophic bacteria and by thermoacidophilic archaea specially at higher temperatures. In this presentation we will discuss the rich biodiversity and complex community structure of the microbial species, bacteria and archaea, that inhabit the Copahue geothermal area, and their corelation with the geology and physicochemical characteristics. This system is a clear example of how the environmental and geochemical condition defined by a mountain, in this particular case, the Copahue volcano, determine the shape and dynamics of the native microbial communities.