Virgibacillus salinus sp. nov., a moderately halophilic bacterium from sediment of a saline lake

A novel, moderately halophilic, Gram-positive bacterium, designated strain XH-22(T), was isolated from sediment of a saline lake located near Xilinhot, Inner Mongolia Autonomous Region, China. Cells were rod-shaped, endospore-forming and motile. The isolate was able to grow in the presence of 3-20 % (w/v) total salts (optimum, 10 %, w/v), and at 15-40 degrees C (optimum, 37 degrees C) and pH 6.0-10.0 (optimum, pH 7.5). Strain XH-22(T) had diaminopimelic acid in the cell-wall peptidoglycan, MK-7 as the predominant menaquinone, and anteiso-C(15 : 0), C(16 : 0) and iso-C(14 : 0) as major fatty acids. The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, a glycolipid and two unidentified phospholipids. The DNA G+C content of strain XH-22(T) was 38.8 mol%. 16S rRNA gene sequence analysis revealed that the novel strain was affiliated with the genus Virgibacillus. Levels of 16S rRNA gene sequence similarity between strain XH-22(T) and the type strains of recognized Virgibacillus species ranged from 97.6 % (with Virgibacillus carmonensis) to 94.9 % (with Virgibacillus koreensis). Levels of DNA-DNA relatedness between strain XH-22(T) and V. carmonensis DSM 14868(T) and Virgibacillus necropolis DSM 14866(T) were 32 and 28 %, respectively. Strain XH-22(T) could be differentiated from recognized Virgibacillus species based on phenotypic characteristics, chemotaxonomic differences, phylogenetic analysis and genotypic features. On the basis of these results, strain XH-22(T) is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus salinus sp. nov. is proposed. The type strain is XH-22(T) (=CCM 7562(T)=CECT 7439(T)=DSM 21756(T)).