Lentilactobacillus laojiaonis sp. nov., isolated from the mud in a fermentation cellar for the production of Chinese liquor
Qiuwei Zhao, Suping Yang, Guanhui Bao, Wenzhao Wang, Liangtian Miao, Songtao Wang, Caihong Shen, Yin Li
Abstract
A novel Gram-stain-positive, rod-shaped, non-motile bacterial strain, designated IM3328 T , was isolated from a mud cellar which has been continuously used over hundreds of years for the fermentative production of Chinese strong-flavour baijiu. It is asporogenous, facultative anaerobic and does not exhibit catalase activity. Strain IM3328 T can grow at pH 4.5–8.5 (optimum, pH 7.0), 15–45 °C (optimum, 37 °C), with 0–75% (w/v) ethanol with and 0–6% (w/v) NaCl. The API 50CH assay revealed that strain IM3328 T can metabolize l -arabinose, d -ribose, d -xylose, d -glucose, d -fructose, d -mannose, N -acetylglucosamine, gluconate, methyl β- d -pyranoside, methyl α- d -glucopyranoside, methyl α- d -glucopyranoside and raffinose among the 49 studied carbon sources. Lactic acid, acetic acid, ethanol, isopentanol and butyl acetate are he predominant metabolites in the fermentation broth of strain IM3328 T when cultured in liquid de Man, Rogosa and Sharpe medium under micro-aerobic or anaerobic conditions. The polar lipids of strain IM3328 T consist of diphosphatidylglycerol, phosphatidylglycerol, one unidentified phospholipid, two unidentified glycolipids and two unidentified lipids. The major cellular fatty acids (≥10%) consist of C 16 : 0 , C 18:1 ω9 c and summed feature 7. The cell wall contains ribose, glucose, galactose, lysine, alanine, glutamic acid and aspartic acid. The complete genome of strain IM3328 T contains a circular chromosome of 1242019 bp with 1242 genes and 33 mol% G+C content. On the basis of the 16S rRNA gene phylogenetic tree, Lentilactobacillus senioris DSM 24302 T (95.9% similarity), Lentilactobacillus rapi DSM 19907 T (95.7% similarity) and Lentilactobacillus parabuchneri DSM 5707 T (95.1% similarity) were chosen to compare with strain IM3328 T to reveal the physiological differences. The low average nucleotide identity values (69.7–71.2%) between strain IM3328 T and phylogenetically related reference strains demonstrated that this strain represents a novel species of the genus Lentilactobacillus , and the name Lentilactobacillus laojiaonis sp. nov. (type strain IM3328 T =CGMCC 1.18832 T =JCM 34630 T ) is proposed.