Faecalimonas umbilicata gen. nov., sp nov., isolated from human faeces, and reclassification of Eubacterium contortum, Eubacterium fissicatena and Clostridium oroticum as Faecalicatena contorta gen. nov., comb. nov., Faecalicatena fissicatena comb. nov and Faecalicatena orotica comb. nov

Two bacterial strains, designated EGH7(T) and TSAH33, were isolated from human faeces and characterized by using a polyphasic taxonomic approach that included analysis of morphology, phenotypic and biochemical features, cellular fatty acid profiles and phylogenetic position based on 16S rRNA and hsp60 gene sequence analyses. The results of 16S rRNA gene sequence analysis indicated that these strains represented members of the family Lachnospiraceae and formed a monophyletic cluster near Eubacterium contortum JCM 6483(T) (95% sequence similarity), Ruminococcus gnavus JCM 6515(T) (95 %), Clostridium oroticum JCM 1429(T) (95 %), Eubacterium fissicatena JCM 31501(T) (95 %) and Clostridium nexile JCM 31500(T) (94 %). The results of a hsp60 gene sequence analysis supported the phylogenetic tree based on the 16S rRNA gene sequence, with a sequence similarity value of between 77.9 and 84.8 % to the five strains listed above. The novel strains were obligately anaerobic, non-pigmented, non-spore-forming, non-motile, Gram-stain-positive cocco-bacilli. The strains formed characteristic umbilicated colonies on EG agar plates. The major cellular fatty acids were C-18 (:) (1)omega 9c, C-16 (:) (0) and C-18 : 1 omega 9c dimethyl acetal (DMA). EGH7(T) and TSAH33 have DNA G+C contents of 46.9 and 45.5 mol%, respectively. On the basis of these data, strains EGH7(T) and TSAH33 represent a novel species of a novel genus, for which the name Faecalimonas umbilicata gen. nov., sp. nov. is proposed. The type strain of F. umbilicata is EGH7(T) (= JCM 30896(T)=DSM 103426(T)).