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 ( approximately 100 %). The distinct characteristics demonstrated 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)).