Abstract

A novel halophilic bacterium, strain K7T, was isolated from kimchi, a traditional Korean fermented food. The strain is Gram-positive, motile, and produces terminal endospores. The isolate is facultative aerobic and grows at salinities of 0.0–25.0% (w/v) NaCl (optimum 10–15% NaCl), pH 5.5–8.5 (optimum pH 7.0–7.5), and 15–42°C (optimum 37°C). The predominant isoprenoid quinone in the strain is menaquinone- 7 and the peptidoglycan of the strain is meso-diaminopimelic acid. The major fatty acids of the strain are anteisio- C15:0, iso-C15:0, and, C16:0 (other components were < 10.0%), while the major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and three unidentified lipids. A phylogenetic analysis of 16S rRNA gene sequence similarity showed that the isolated strain was a cluster of the genus Gracilibacillus. High levels of gene sequence similarity were observed between strain K7T and Gracilibacillus orientalis XH-63T (96.5%), and between the present strain and Gracilibacillus xinjiangensis (96.5%). The DNA G+C content of this strain is 37.7 mol%. Based on these findings, strain K7T is proposed as a novel species: Gracilibacillus kimchii sp. nov. The type strain is K7T (KACC 18669T; JCM 31344T).

• Keywords: Gracilibacillus kimchii sp. nov.; halophile; kimchi; korean fermented food; taxonomy