Clostridium liquoris sp. nov., isolated from a fermentation pit used for the production of Chinese strong-flavoured liquor.

Abstract

Strain BEY10T was isolated from an old fermentation pit, which had been used for the production of Chinese strong-flavoured liquor for over 20 years. The strain was strictly anaerobic, Gram-stain positive, rod-shaped, non-motile and spore-forming. Strain BEY10T grew at temperatures of 22-47 °C (optimum 37 °C), at pH 5.5-9.0 (optimum pH 7.5-8.5) and with NaCl concentrations of 0-4 % (w/v) (optimum 0 %). The isolate was able to utilize glucose, mannitol, lactose, xylose, maltose, glycerol, cellobiose and trehalose as carbon sources for growth. The major end-products from glucose fermentation were ethanol and butyric acid. The polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, phospholipids, a glycolipid and an aminolipid. The predominant fatty acids (>10 %) were C20 : 0, C18 : 0, C16 : 0, C12 : 0 and C14 : 0. The DNA G+C content was 34.4 mol%. Sequence analysis of the 16S rRNA gene indicated that strain BEY10T belongs to the genus Clostridium in the family Clostridiaceae. The closest phylogenetic neighbour is Clostridium lundense DSM 17049T, showing 97.6 % 16S rRNA gene sequence similarity with strain BEY10T. DNA-DNA relatedness values of strain BEY10T with Clostridium lundense DSM 17049T, Clostridium tetanomorphum DSM 4474T and Clostridium pascui DSM 10365T were 58.8 %, 57.9 % and 42.2 %, respectively. This characterization based on phylogenetic, phenotypic and chemotaxonomic evidence demonstrated that strain BEY10T represents a novel species of the genus Clostridium, for which the name Clostridium liquoris sp. nov. is proposed. The type strain is BEY10T ( = ACCC 00785T = DSM 100320T).