Summary: | El autor González Grau, Juan Miguel pertenece actualmente al Instituto de Recursos Naturales y Agrobiología de Sevilla Carbon monoxide is regarded as the common component of volcanic gasesboth in terrestrial and deep-sea environments. A variety of diverse bacteria pos-sess CO-oxidizing enzymes termed CO dehydrogenases which allow them to uti-lise CO as a sole source of carbon and energy. Oxygen-dependent CO oxidation isa well known process carried out by a voluminous group of aerobiccarboxydobacteria described by Zavarzin and Nozhevnikova (1977) and by Meyeret al. (1986). In anoxic environments CO could be oxidized by acetogenic bacteriawith acetate production (Wood and Ljungdahl, 1991; Ljungdahl, 1994; Drake,1994), or by methanogenic bacteria with methane production (Deppenmeier et al.,1996; Ferry, 1999).At the beginning of nineties a process of anaerobic CO oxidation resultingin production of hydrogen and carbon dioxide according to the reactionCO + H2O = CO2 + H2was found in thermophilic bacteria (Svetlichny et al., 1991). The aim of our workwas the description of anaerobic thermophilic CO-oxidizing H2-producing micro-organisms from volcanic environments.From terrestrial hot springs of Kamchatka, Yellowstone, Kuril and KermadecIslands and Baikal region, deep-sea hot vents of West and East Pacific oceanssamples of hot water and mud were taken anaerobically and stored in tightlystoppered bottles. The samples were inoculated in anaerobically prepared me-dium under atmosphere of CO at temperatures 60, 70, 80, and 85 oC. Freshwater(Svetlichny et al., 1991) or marine (Sokolova et al., 2001) medium were used. Gas-eous and liquid fermentation products were detected by GLC. Phylogenetic posi-tion was determined by 16S rDNA sequencing (Sokolova et al., 2001). Peer reviewed
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