A thermophillic, non-spore-forming, marine, sulfate-reducing bacterium, strain SL6(T), was isolated from deep-sea hydrothermal sulfides collected at Guaymas Basin. The Gram-negative-staining cells occurred singly or in pairs as small, highly motile rods. The temperature range for growth was 50-80degreesC with an optimum at 75degreesC. The pH range for growth at 70degreesC was 6.3-6.8, with an optimum at 6.5. The NaCl concentration range for growth was 5.55 g l(-1), with an optimum at 30 g l(-1). H-2 and CO2 were the only substrates for growth and sulfate reduction. However, growth was stimulated by several organic compounds. Sulfur, thiosulfate, sulfite, cystine, nitrate and fumarate were not used as electron acceptors. Pyruvate, lactate and malate did not... |