Description of Mediterraneibacter massiliensis, gen. nov., sp nov., a new genus isolated from the gut microbiota of an obese patient and reclassification of Ruminococcus faecis, Ruminococcus lactaris, Ruminococcus torques, Ruminococcus gnavus and Clostridium glycyrrhizinilyticum as Mediterraneibacter faecis comb. nov., Mediterraneibacter lactaris comb. nov., Mediterraneibacter torques comb. nov., Mediterraneibacter gnavus comb. nov and Mediterraneibacter glycyrrhizinilyticus comb. nov.

An anaerobic isolate, strain AT7(T), was cultivated from a stool sample of a morbidly obese French woman using a microbial culturomics approach. The 16S rRNA gene sequence analysis showed that strain AT7(T) exhibited 96% nucleotide sequence similarity with Ruminococcus torques strain JCM 6553(T) (=ATCC 27756(T)=VPI B2-51(T)), currently the closest related species with a validly published name. The strain was observed to be a Gram-stain positive, non-motile, asporogenous and coccobacillary-shaped bacterium. It was found to be catalase positive and oxidase negative. Its major fatty acids were identified as C-16:0 (54%) and C-18:1n9 (30%). The draft genome of strain AT7(T) is 3,069,882bp long with 42.4% G+C content. 2925 genes were predicted, including 2867 protein-coding genes and 58 RNAs. Based on phenotypic, biochemical, phylogenetic and genomic evidence, we propose the creation of the new genus Mediterraneibacter and species, Mediterraneibacter massiliensis, that contains strain AT7(T) (=CSUR P2086(T)=DSM 100837(T)), and the reclassification of Ruminococcus faecis, Ruminococcus lactaris, Ruminococcus torques, Ruminococcus gnavus, Clostridium glycyrrhizinilyticum as Mediterraneibacter faecis comb. nov., with type strain Eg2(T) (=KCTC 5757(T)=JCM15917(T)), Mediterraneibacter lactaris comb. nov., with type strain ATCC 29176(T) (=VPI X6-29(T)), Mediterraneibacter torques comb. nov., with type strain ATCC 27756(T) (=VPI B2-51(T)), Mediterraneibacter gnavus comb. nov., with type strain ATCC 29149T (=VPI C7-9T) and Mediterraneibacter glycyrrhizinilyticus comb. nov., with type strain ZM35(T) (=JCM 13368(T)=DSM 17593(T)), respectively.