Abstract
A new moderately thermophilic, alkaliphilic, sulfate-reducing, chemolithoheterotrophic bacterium, strain S1(T), was isolated from a mixed cow/pig manure with neutral pH. The bacterium is an obligately anaerobic, non-motile, Gram-positive, spore-forming curved rod growing within a pH range of 8.0--9.15 (optimal growth at pH 8.6--8.7) and temperature range of 30--58 degrees C (optimal growth at 50--55 degrees C). The optimum NaCl concentration for growth is 0.1%. Strain S1(T) is an obligately carbonate-dependent alkaliphile. The G+C content of the DNA is 40.9 mol%. A limited number of compounds are utilized as electron donors, including H(2)+acetate, formate, ethanol, lactate and pyruvate. Sulfate, sulfite and thiosulfate, but not sulfur or nitrate, can be used as electron acceptors. Strain S1(T) is able to utilize acetate or yeast extract as sources of carbon. Analysis of the 16S rDNA sequence allowed strain S1(T) (=DSM 12257(T)) to be classified as a representative of a new species of the genus Desulfotomaculum, Desulfotomaculum alkaliphilum sp. nov.