Clostridium aromativorans sp. nov., isolated from pit mud used for producing Wuliangye baijiu.

Abstract

A strictly anaerobic, gram-positive bacterium, designated as WLY-B-L2T, was isolated from pit mud of a fermentation pit located at Wuliangye 501# baijiu workshop in Yibin (Sichuan province, PR China). The strain was strictly anaerobic, Gram-positive with straight or somewhat rod shaped cells which were 0.5-0.7μm wide and 1.7-3.1μm long, arranged singly or in pairs. The strain can utilize D-galacturonic acid, methyl pyruvate, L-lactamine, L-alanyl - L-glutamine, L-alanyl - L-histidine, glycerol, pyruvate, L-alanyl - L-threonine, L-methionine, L-phenylalanine, L-valine + L-aspartic acid, L-serine, L-valine, and thymidine as carbon sources. Major cellular fatty acids are C16: 0 (24.6%), anteiso-C15: 0 (16.5%), and iso-C15: 0 (14.1%). Based on 16S rRNA gene sequence, WLY-B-L2T is most closely related to Clostridium luticellarii FW431T; they exhibit 97.42% 16S rRNA similarity. Additionally, the digital DNA-DNA hybridization (dDDH) value between them is 28.10%. WLY-B-L2T has a G + C content of 34.16mol%. Based on the evidence presented here, WLY-B-L2T (CICC 25133T = JCM 35127T) is proposed as the type strain of a novel species, designated as Clostridium aromativorans sp. nov, that could produce butyric acid and volatile flavor components, such as ethyl valerate, ethyl acetate and 2-pentanone.