Haloanaerobium alcaliphilum sp. nov., an anaerobic moderate halophile from the sediments of Great Salt Lake, Utah.

A strictly anaerobic, moderately halophilic, gram-negative, rod-shaped bacterium was isolated from Great Salt Lake, Utah, sediments and designated GSLST (T = type strain). Strain GSLST grew optimally at pH 6.7 to 7.0 but had a very broad pH range for growth (pH 5.8 to 10.0). The optimum temperature for growth was 37 degrees C, and no growth occurred at 15 or 55 degrees C. The optimum salt concentration for growth was 10%. Strain GSLST required yeast extract and Trypticase peptone to ferment carbohydrates, pyruvate, and glycine betaine. Strain GSLST was resistant to penicillin, D-cycloserine, tetracycline, and streptomycin. The G + C content of this isolate was 31 mol%. The fermentation products from glucose utilization were acetate, butyrate, lactate, CO2, and H2, and in addition strain GSLST fermented glycine betaine to acetate and trimethylamine. All of these traits distinguish this organism from all previously described halophilic anaerobes. The 16S rRNA gene sequence of strain GSLST was found to be similar to, but also significantly different from, the 16S rRNA sequences of Haloanaerobium salsugo and Haloanaerobium praevalens. Therefore, strain GSLST (= DSM 8275T) is described as a new species, Haloanaerobium alcaliphilum.