Gracilibacillus ureilyticus sp. nov., a halotolerant bacterium from a saline-alkaline soil.

Abstract

A Gram-stain-positive, halotolerant, neutrophilic, rod-shaped bacterium, strain MF38(T), was isolated from a saline-alkaline soil in China and subjected to a polyphasic taxonomic characterization. The isolate grew in the presence of 0-15 % (w/v) NaCl and at pH 6.5-8.5; optimum growth was observed with 3.0 % (w/v) NaCl and at pH 7.0. Chemotaxonomic analysis showed menaquinone MK-7 as the predominant respiratory quinone and anteiso-C(15 : 0), anteiso-C(17 : 0), iso-C(15 : 0), C(17 : 0) and C(16 : 0) as major fatty acids. The genomic DNA G+C content was 35.3 mol%. 16S rRNA gene sequence similarities of strain MF38(T) with type strains of described Gracilibacillus species ranged from 95.3 to 97.7 %. Strain MF38(T) exhibited the closest phylogenetic affinity to the type strain of Gracilibacillus dipsosauri, with 97.7 % 16S rRNA gene sequence similarity. The DNA-DNA reassociation between strain MF38(T) and G. dipsosauri DSM 11125(T) was 45 %. On the basis of phenotypic and genotypic data, strain MF38(T) represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus ureilyticus sp. nov. (type strain MF38(T) =CGMCC 1.7727(T) =JCM 15711(T)) is proposed.