A novel Gram-stain-positive, rod-shaped, obligately anaerobic, non-motile, spore-forming and binary fission encapsulated bacterium, designated strain JN500901T, was isolated from a mud cellar which has been continuously used for the fermentation of Chinese strong-flavour baijiu for over 100 years. Growth of JN500901Toccurred at pH 4.5-8.0 (optimum, pH 5.0), 20-40 °C (37 °C), 0-2 % (w/v) NaCl and 0-10 % (v/v) ethanol. The Biolog assay revealed that strain JN500901T metabolized d-fructose, l-fucose, isomaltulose and l-rhamnose among the 95 studied carbon sources. p-Cresol was the predominant volatile metabolite in the fermentation broth of strain JN500901T incubated in liquid reinforced clostridial medium under anaerobic conditions. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JN500901T belongs to Clostridiumsensu stricto, and shared the highest sequence similarity to Clostridiumcarboxidivorans DSM 15243T (94.2 %), followed by Clostridiumscatologenes DSM 757T (94.1 %). The dominant cellular fatty acids (>10 %) were C16 : 0 FAME (36.6 %), C19 : 0 cyc 9,10 DMA (19.8 %) and C16 : 1 cis 9 DMA (11.8 %). The complete genome of strain JN500901T contained a circular chromosome of 2.812 Mb with 2611 genes and 31.0 mol% G+C content. Comparative genome analysis of the strain JN500901T, Clostridiumcarboxidivorans DSM 15243T and Clostridiumscatologenes DSM 757T revealed 74.5 and 74.8 % average nucleotide identity, respectively. Based on the phenotypic, biochemical and phylogenetic analyses presented here, strain JN500901T is considered to be a novel species of the genus Clostridiumsensustricto, for which the name Clostridium fermenticellae sp. nov. is proposed. The type strain is JN500901T (=CICC 24501T=JCM 32827T).
Keywords: Clostridium sensu stricto; fermentation pit mud; p-cresol; strong-flavor baijiu.