Acidaminococcus nyctereutis sp. nov., a bacterium isolated from the gut of a raccoon dog (Nyctereutes procyonoides)

A strictly anaerobic bacterial strain, designated LBK-2 T , was isolated from the intestinal tract of a raccoon dog. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LBK-2 T shared the highest similarity (99.3 –95.0 %) with type strains in the genus Acidaminococcus . The cells were coccoid, Gram-negative, non-motile and non-haemolytic. They tested negative for oxidase and catalase but positive for alkaline phosphatase. Growth occurred at 20–50℃ (optimum: 37 ℃), pH 3.5–8.0 (optimum: pH 7.0) and 0–2 % NaCl. Major fatty acids include C 16 : 1 ω 9c , C 18 : 1 ω 9c , C 12 : 0 and C 12 : 0 aldehyde. The average nucleotide identity and digital DNA–DNA hybridization values between LBK-2 T and type strains of other Acidaminococcus species ranged from 64.83 to 88.25 % and 18.0 to 64.6 %, respectively, both below the species delineation thresholds. The genomic DNA G+C content was 53.6 %. Based on polyphasic taxonomic evidence, strain LBK-2 T (=CGMCC 1.18153 T =KCTC 25959 T ) represents a novel species within the genus Acidaminococcus , for which the name Acidaminococcus nyctereutis sp. nov. is proposed.