Virgibacillus halophilus sp. nov., spore-forming bacteria isolated from soil in Japan

Abstract

Two Gram-positive, round-spore-forming, rod-shaped, halophilic bacterial strains, 5B73C(T) and 5B133E, were isolated from field soil in Kakegawa, Shizuoka, Japan, and were characterized taxonomically using a polyphasic approach. These two strains were found to comprise strictly aerobic, motile rods that formed subterminal endospores. Phylogenetic analyses based on 16S rRNA gene sequences showed that strains 5B73C(T) and 5B133E are phylogenetically affiliated to the genus Virgibacillus, exhibiting sequence similarities of 94.1-96.4 % with respect to the type strains of Virgibacillus species. The DNA G+C contents of strains 5B73C(T) and 5B133E were 42.6 and 42.3 mol%, respectively. The cell-wall peptidoglycan type (meso-diaminopimelic acid), the major cellular fatty acids (anteiso-C(15 : 0), iso-C(15 : 0), anteiso-C(17 : 0) and iso-C(16 : 0)) and the quinone type (MK-7) of the isolates support their affiliation to the genus Virgibacillus. On the basis of their genotypic and phenotypic characteristics, the isolates represent a novel species of the genus Virgibacillus, for which the name Virgibacillus halophilus sp. nov. is proposed. The type strain is 5B73C(T) (=IAM 15308(T)=KCTC 13935(T)).