Halobacillus dabanensis sp. nov. and Halobacillus aidingensis sp. nov., isolated from salt lakes in Xinjiang, China

Abstract

Two moderately halophilic spore-forming bacteria were isolated from salt lakes in the Xinjiang region of China. The two strains, designated AD-6(T) and D-8(T), were aerobic, Gram-positive, rod-shaped and motile by means of peritrichous flagella. Strains AD-6(T) and D-8(T) grew in the presence of 0.5-20% and 0.5-25% (w/v) NaCl in complex medium, respectively. Their cell-wall peptidoglycan was of the L-Orn-D-Asp type. The major menaquinone found in both strains was menaquinone-7 (MK-7). The fatty acid profile contained a large amount of branched fatty acids; the main fatty acids were anteiso-C(15:0), anteiso-C(17:0), iso-C(15:0) and iso-C(16:0). The DNA G+C content of strains D-8(T) and AD-6(T) was 41.4 and 42.2 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains D-8(T) and AD-6(T) were located in the genus Halobacillus. Levels of 16S rRNA gene sequence similarity between the isolated strains and the type strains of Halobacillus species were in the range 96.2-99.5%. DNA-DNA relatedness values of 17.0-52.2% were found between the two strains and other Halobacillus species. The DNA-DNA relatedness value between D-8(T) and AD-6(T) was 50.6%. On the basis of phenotypic and chemotaxonomic properties, phylogenetic analysis and genomic distinctiveness, strains D-8(T) and AD-6(T) should be placed in the genus Halobacillus as two novel species, for which the names Halobacillus dabanensis sp. nov. (type strain=JCM 12772(T)=CGMCC 1.3704(T)) and Halobacillus aidingensis sp. nov. (type strain=JCM 12771(T)=CGMCC 1.3703(T)) are proposed, respectively.