Characterization of a New Thermophilic Sulfate-Reducing Bacterium 'Thermodesulfovibrio yellowstonii' gen. nov. and sp. nov.: Its Phylogenetic Relationship to 'Thermodesulfobacterium commune' and Their Origins Deep within the Bacterial Domain

摘要

A thermophilic sulfate-reducing vibrio isolated from thermal vent water in Yellowstone Lake, Wyoming, USA is described. The gram-negative, curved rod-shaped cells averaged 0.3 micrometers wide and 1.5 micrometers 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. Desulfofuscidin and c-type cytochromes were present. The G + C content was 29.5 mol%. The divergence in the 16S ribosomal RNA sequences between the new isolate and Thermodesulfobacterium commune sugggests that these two thermophilic sulfate-reducing bacteria represent different genera. These two bacteria depict a lineage that branches deeply within the Bacteria domain and which 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.