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

Abstract

A Gram-stain-positive, halotolerant, neutrophilic, rod-shaped bacterium, strain MF38T, 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-C15 : 0, anteiso-C17 : 0, iso-C15 : 0, C17 : 0 and C16 : 0 as major fatty acids. The genomic DNA G+C content was 35.3 mol%. 16S rRNA gene sequence similarities of strain MF38T with type strains of described Gracilibacillus species ranged from 95.3 to 97.7 %. Strain MF38T 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 MF38T and G. dipsosauri DSM 11125T was 45 %. On the basis of phenotypic and genotypic data, strain MF38T represents a novel species of the genus Gracilibacillus, for which the name Gracilibacillus ureilyticus sp. nov. (type strain MF38T =CGMCC 1.7727T =JCM 15711T) is proposed.