Lysinibacillus xyleni sp. nov., isolated from a bottle of xylene

Abstract

A Gram-staining-positive, solvent-tolerating (acetophenone, benzene, toluene, xylene and hexane), aerobic, non-motile, terminal endospore-forming, rod-shaped bacterium was isolated from a bottle of xylene. The strain, designated JC22T, was found to be oxidase and catalase positive. The strain was able to tolerate solvents with different log p values like acetophenone (log P = 1.5), benzene (log P = 2.0), toluene (log P = 2.5), xylene (log P = 3.2) and hexane (log P = 3.4), though it could not use them as sole carbon sources. Based on the 16S rRNA gene sequence analysis, strain JC22T was identified as belonging to the genus Lysinibacillus and was most closely related to Lysinibacillus sinduriensis BLB-1T (98.1 %), Lysinibacillus halotolerans LAM612T (97.8 %), Lysinibacillus chungkukjangi 2RL3-2T (97.6 %) and Lysinibacillus xylanilyticus XDB9T (97.1 %). The DNA–DNA relatedness of strain JC22T with the type strains of closest species was < 30 %. Strain JC22T grew chemoorganoheterotrophically with an optimal pH of 7–8 (range 6–10) at 35–37 °C (range 25–40 °C). The DNA G+C content was 41.2 mol%. The major cellular fatty acids were iso-C15:0, anteiso-C15:0 and iso-C16:0. Cell wall peptidoglycan type was determined to be A4α (l-Lys–d-Asp). Predominant quinone system was MK-7 with moderate amounts of MK-6, MK-6(H2) and MK-7(H2). Polar lipids of strain JC22T contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. On the basis of morphological, physiological, genetic, phylogenetic and chemotaxonomical analyses, we conclude that strain JC22T be assigned the status of novel species of the genus Lysinibacillus for which the name Lysinibacillus xyleni sp. nov. is proposed. Type strain of the species is JC22T (= CCUG 57912T = KCTC 13604T = NBRC 105753T = DSM 23555T).