First assessment of acidophilic microorganisms from geothermal Copahue–Caviahue system

This work presents an overview of the physicochemical and biological studies focusing on acidophilic microorganisms carried out along Rio Agrio and in different hot springs belonging to the geothermal Copahue–Caviahue system (Neuquén Argentina). This extreme environment is characterized by wide ranges of temperature and pH (< 1 to 8) and the presence of heavy metals. In these extreme conditions chemolitho-autotrophic and -heterotrophic bacteria, archaea, yeasts and filamentous fungi were detected. Strains of Leptospirillum ferrooxidans, Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidianus spp., among others, were successfully cultivated. Some physiological properties of the isolates and several biotechnological applications of them were studied and the main results are presented in this paper.