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 desi gnated 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 occ urred 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 strep tomycin. The G+C content of this isolate was 31 mol%. The fermentation products from glucose utilization were acetate, butyrate, lactate, CO 2, and H-2, and in addition strain GSLS(T) fermented glycine betaine t o acetate and trimethylamine. All of these traits distinguish this org anism 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) (= D SM 8275(T)) is described as a new species, Haloanaerobium alcaliphilum .