Research Product

A thermophilic sulfate-reducing vibrio isolated from thermal vent water in Yellowstone Lake, Wyoming USA, is described. The gram-negative, curve rod-shaped cells averaged 0.3 µm wide and 1.5 µm long. They were motile by means of a single polar flagellum. Growth was observed between 40° and 70°C with optimal growth at 65°C. Cultures remained viable for one year at 27°C although spore-formation was not observed. In the presence of sulfate, growth was observed only with lactate, pyruvate, hydrogen plus acetate, or formate plus acetate. Pyruvate was the only compound observed to support fermentative growth. Pyruvate and lactate were oxidized to acetate. Desulfofuscidin and c-type cytochromes were present. The G plus C content was 29.5 mol%. The divergence in the 16S ribosomal RNA sequences between the new isolate and Thermodesulfobacterium commune suggests that these two thermophilic sulfate-reducing bacteria represent different genera. These two bacteria depict a lineage that branches deeply within the Bacteria domain and is clearly distinct from previously defined phylogenetic lines of sulfate-reducing bacteria. Strain YP87 is described as the type strain of the new genus and species Thermodesulfovibrio yellowstonii.