Haloanaerobacter salinarius sp. nov., a novel halophilic fermentative bacterium that reduces glycine-betaine to trimethylamine with hydrogen or serine as electron donors; emendation of the genus Haloanaerobacter

A novel halophilic fermentative bacterium has been isolated from the black sediment below a gypsum crust and a microbial mat in hypersaline ponds of Mediterranean salterns, Morphologically, physiologically and genetically this organism belongs to the genus Haloanaerobacter, Haloanaerobacter strain SG 3903(T) (T = type strain) is composed of non-sporulating long flexible rods with peritrichous flagella, able to grow in the salinity range of 5-30% NaCl, with an optimum at 14-15%. The strain grows by fermenting carbohydrates or by using the Stickland reaction with either serine or H-2 as electron donors and glycine-betaine as acceptor, which is reduced to trimethylamine. The two Species described so far in the genus Haloanaerobacter are not capable of Stickland reaction with glycine-betaine + serine; however, Haloanaerobacter chitinovorans can use glycine-betaine with H-2 as electron donor. Strain SC 3903(T) thus represents the first described strain in the genus Haloanaerobacter capable of the Stickland reaction with two amino acids. Although strain SC 3903(T) showed 67% DNA-DNA relatedness to H. chitinovorans, it is physiologically sufficiently different from the two described species to be considered as a new species which has been named Haloanaerobacter salinarius sp, nov.