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 GSLS(T) (T = type strain). Strain GSLS(T) 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 GSLS(T) required yeast extract and Trypticase peptone to ferment carbohydrates, pyruvate, and glycine betaine. Strain GSLS(T) 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 H-2, and in addition strain GSLS(T) 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 GSLS(T) was found to be similar to, but also significantly different from, the 16S rRNA sequences of Haloanaerobium salsugo and Haloanaerobium praevalens. Therefore, strain GSLS(T) (= DSM 8275(T)) is described as a new species, Haloanaerobium alcaliphilum.