Halobacillus gen. nov., with Descriptions of Halobacillus litoralis sp. nov. and Halobacillus trueperi sp. nov., and Transfer of Sporosarcina halophila to Halobacillus halophilus comb. nov.

Abstract

Two moderately halophilic, gram-positive, heterotrophic bacterial strains were isolated from hypersaline sediments of the Great Salt Lake in Utah. These two strains, designated SL-4T (T = type strain) and SL-5T, were motile, spore-forming, strictly aerobic rods which contained peptidoglycan of the Orn-d-Asp type in their vegetative cell walls. The guanine-plus-cytosine contents of the DNAs of strains SL-4T and SL-5T were 42 and 43 mol%, respectively. A detailed investigation of the phenotypic and phylogenetic characteristics of these organisms revealed that each isolate represents a new species that is closely related to Sporosarcina halophila, a moderately halophilic, spore-forming coccus. Phylogenetic data indicate that there is only a distant relationship between Sporosarcina halophila and Sporosarcina ureae, the type species of the genus Sporosarcina. The sequences of the 16S rRNA genes of strain SL-4T and Salinicoccus roseus DSM 5351 were determined. We propose that a new genus, Halobacillus, should be created; this genus includes Halobacillus halophilus (formerly Sporosarcina halophila) as the type species, as well as Halobacillus litoralis DSM 10405T (= SL-4T) and Halobacillus trueperi DSM 10404T (= SL-5T).