Gracilibacillus eburneus sp.nov., a moderately halophilic bacterium isolated from Xinjiang province, China.

Abstract

A novel Gram-staining positive, moderately halophilic, endospore-forming, motile, rod-shaped and strictly aerobic strain, designated YIM 93565T, was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93565T grew in the range of pH 6.0-9.0 (optimum pH 7.0), 10-45 °C (optimum 35-40 °C) and at salinities of 2-24% (w/v) NaCl (optimum 7-10%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 93565T clustered with members of the genera Gracilibacillus and form a clade with Gracilibacillus bigeumensis KCTC 13130T (95.6% similarity) and Gracilibacillus halophilus DSM 17856T (94.9%), which was well separated from others. The DNA G + C content of this novel strain was 36.8 mol%. The major fatty acids were anteiso-C15:0, iso-C15:0, C16:0 and anteiso-C17:0 and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid and two unidentified phospholipids. The predominant menaquinone was MK-7. The cell-wall peptidoglycan was based on meso-diaminopimelic acid. Based on the results of phylogenetic, physiological and chemotaxonomic comparative analyses, the isolate is assigned to a novel species of the genus Gracilibacillus, for which the name Gracilibacillus eburneus sp. nov. is proposed, with the type strain YIM 93565T (= DSM 23710T = CCTCC AB 2013249T).