Virgibacillus salarius sp nov., a halophilic bacterium isolated from a Saharan salt lake

A Gram-positive, endospore-forming, rod-shaped and moderately halophilic bacterium was isolated from a salt-crust sample collected from Gharsa salt lake (Chott el Gharsa), Tunisia. The newly isolated bacterium, designated SA-Vb1(T), was identified based on polyphasic taxonomy including genotypic, phenotypic and chemotaxonomic characterization. Strain SA-Vb1(T) was closely related to the type strains of Virgibacillus marismortui and Virgibacillus olivae, with 16S rRNA gene sequence similarities of 99.7 and 99.4%, respectively. However, strain SA-Vb1(T) was distinguished from these two type strains on the basis of phenotypic characteristics and DNA-DNA relatedness (29.4 and 5.1%, respectively). The genetic relationship between strain SA-Vb1(T) and Virgibacillus pantothenticus IAM 11061(T) (the type strain of the type species) and other type strains of the genus was 96-98% based on 16S rRNA gene sequence similarity and 18.3-22.3% based on DNA-DNA hybridization. Biochemical analysis resulted in determination of major fatty acids iso-C-15:0, anteiso-C-15:0 and anteiso-C-17:0 (33.3, 29.2 and 9.8%, respectively); phosphatidylglycerol, diphosphatidylglycerol and phosphatidylethanolamine were the main polar lipids and MK-7 was the predominant menaquinone (similar to 100%). The distinct characteristics demostrated by strain SA-Vb1(T) represent properties of a novel species of the genus Virgibacillus, for which the name Virgibacillus salarius sp. nov. is proposed. The type strain is SA-vb1(T) (=JCM 12946(T) =DSM 18441(T)).