Lithotrophic and Acetate-Oxidizing Anaerobes from Terrestrial Hot Vents
Elizaveta A. BONCH-OSMOLOVSKAYA*, Margarita L. MIROSHNICHENKO, Aleksandr I.SLOBODKIN, and Tatyana G. SOKOLOVA
Department of Microbial Communities, Institute of Microbiology, Russian Academy of Sciences, prospect 60 Letiya Oktyabrya 7/2, 117811 Moscow, Russia
Lithotrophic and acetate-oxidizing anaerobic thermophiles were enriched and isolated from samples of Kamchatka thermal areas with different pH and temperatures. It was found that rod-shaped hydrogen-utilizing methanogens are present at temperature 55 - 85℃ and pH 6.5 - 8.5. New thermophilic sulfate- and sulfur-reducing bacteria and archaea were described, which utilize H2 and acetate at 55 - 85℃ and pH 4.0 - 8.5. The process of microbial reduction of Fe (III) with H2 and acetate as electron donors was found to be wide-spread in hot vents with different pH and temperature. Magnetite formation in the course of growth was observed. Anaerobic CO oxidation coupled with H2 formation from water was registered in neutral hot springs with to 55 - 85℃. These results demonstrate the diversity of thermophilic anaerobic processes of lithoautotrophy and acetate oxidation, which may well contribute to primary production and organic matter mineralization in different type hot vents.