Lawsonibacter asaccharolyticus gen. nov., sp. nov., a butyrate-producing bacterium isolated from human faeces

An obligately anaerobic, Gram-positive, non-spore-forming, straight rod-shaped bacterium, designated strain 3BBH22^T, was isolated from a faecal sample of a healthy Japanese woman. The 16S rRNA gene sequence analysis showed that strain 3BBH22^T formed a monophyletic cluster with species in the genera Pseudoflavonifractor and Flavonifractor within the family Ruminococcaceae and had highest similarity to Pseudoflavonifractor capillosus ATCC 29799^T (96.7 % sequence similarity), followed by Flavonifractor plautii ATCC 29863^T (96.4 %). Acetate and butyrate were produced by strain 3BBH22^T as metabolic end-products. The major cellular fatty acids were C14 : 0, C16 : 0, C18 : 1ω9c, C16 : 0 dimethyl acetal, C18 : 0 and C18 : 2ω6,9c. No respiratory quinones were detected. In contrast to F. plautii JCM 32125^T, strain 3BBH22^T did not degrade quercetin, one of the flavonoids. P. capillosus JCM 32126^T also did not. Strain 3BBH22^T was differentiated from P. capillosus JCM 32126^T by its inability to hydrolyse aesculin. The G+C content of the genomic DNA was 61.2±1.0 mol%. On the basis of these data and the phylogenetic tree based on 89 proteins, strain 3BBH22^T represents a novel species in a novel genus of the family Ruminococcaceae, for which the name Lawsonibacter asaccharolyticus gen. nov., sp. nov. is proposed. The type strain of L. asaccharolyticus is 3BBH22^T (=JCM 32166^T=DSM 106493^T).