Biodiversity in the Copahue geothermal region; a study case of biogeography and community structure of acidic and thermophilic extremophiles

URBIETA, M. S.

Bogotá

Congreso; II Edición del Congreso ISME Latinoamericano ISME Lat 2021; 2021

Universidad de los Andes

The Copahue geothermal area is located on the Northwest of Neuquén province (Patagonia, Argentina). It is a naturally extreme environment dominated by the still active Copahue volcano, whose cyclic eruptive periods shape the landscape and its physicochemical characteristics. The area, of approximately 250 Km2, has two different zones: the Copahue volcano-Río Agrio system and the geothermal ponds. Río Agrio is a natural acidic river of geothermal origin that maintains low pH values for almost its entire path, despite receiving many tributary neutral water courses. The results of different biodiversity studies show that Rio Agrio is dominated by ubiquitous acidophilic, sulphur and/or iron oxidising chemolitoautotrophic species, which have been isolated from similar environments around the world; however, there are also autochthonous species, many of them yet uncultured. On the other hand, the geothermal manifestations are a constantly changing environment, highly dependent on the volcanic activity. There are pools, ponds and hot springs in a wide range of temperature and pH. In general, the acidic ponds are also dominated by acidophilic chemolitoautotrophic species, more frequently associated with acid mine drainages than geothermal environments and by thermoacidophilic archaea, specially at higher temperatures. According to our comprehensive biostatistical analysis the microbial community structure of geothermal areas is extremely complex and could not only be determined by temperature or pH; other shaping factors such as sediment composition or even location (which inevitably includes sampling and methodological bias) need to be considered. However, there seem to be specific taxa strongly associated with certain conditions of pH and temperature widely distributed around the world. Our results show that the biodiversity of extreme environments is a still interesting topic with much yet unknown, and particularly confirm the relevance of Copahue geothermal region as a study case and the habitat of novel microbial species of biotechnological and scientific relevance.