sp. nov., an anaerobic mucin-degrading bacterium isolated from human faeces.

A bacterial strain, WON2089, was isolated from the faeces of healthy Japanese adults and is able to use mucin as the sole carbon and nitrogen source. Sequencing of its 16S rRNA gene showed that WON2089 has 98.0 and 94.4% similarity to Muc and Pyt, respectively, while phylogenetic tree analysis confirmed that it belongs to the genus . The whole genome of WON2089 was sequenced, which showed that it shares 84.5 % average nucleotide identity (ANI) and 24.9 % digital DNA-DNA hybridization (dDDH) with its closest relative, Muc. Cells of WON2089 are non-motile, anaerobic and oval-shaped (0.4-0.5×0.5-1.0 µm). The strain is Gram-stain-negative and grows in the temperature range of 25-45 °C (optimum, 30-37 °C) and pH range of pH 5.5-9.5 (optimum, pH 6.5-8.0). WON2089 can utilize d-glucose, d-mannitol, lactose and d-mannose, as assessed by API20A strips. The major cellular fatty acids are C anteiso, C 3OH and C ω9 (55.5, 7.5 and 5.8 % of total fatty acids, respectively). Based on 16S rRNA sequencing, ANI, dDDH and acid formation from d-mannitol, WON2089 is distinct from previously reported species of the genus . Based on phenotypic, phylogenetic and genetic characteristics, WON2089 represents a novel species of the genus and the name sp. nov. is proposed. The type strain is WON2089 (= NBRC 115679= DSM 114407).