Anaerostipes Faecalis Sp. Nov. Isolated from Swine Faeces

A novel, strictly anaerobic, gram-negative, segmented filamentous bacterium (SFB), strain AGMB03513T, was isolated from the faeces of a 5-month-old pig. Comparative analysis of 16S rRNA gene sequences indicated that strain AGMB03513T forms a lineage within the genus Anaerostipes and is most closely related to Anaerostipes butyraticus DSM 22094T (= KCTC 15125T, 95.8%), Anaerostipes hadrus DSM 3319T (= KCTC 15606T, 95.5%), Anaerostipes caccae DSM 14662T (= KCTC 15019T, 94.0%), and Anaerostipes rhamnosivorans DSM 26241T (= KCTC 15316T, 93.4%). Phylogenetic analysis based on the 16S rRNA gene and whole genome sequencing analysis revealed that its closest relatives are members of the family Lachnospiraceae and that the closest related is Anaerostipes butyraticus. Strain AGMB03513T grows at temperatures of between 30 and 45°C within a pH range of 7.0 to 9.0, and in medium containing up to 1.5% NaCl. Cells were found to utilize d-glucose, d-mannitol, d-lactose, d-saccharose, d-maltose, d-xylose, l-arabinose, d-mannose, and d-sorbitol, and acetate was identified as the major end product of metabolism. The DNA G+C content of the strain is 37.0 mol%. Average nucleotide identity (ANI) values obtained in comparisons of strain AGMB03513T with reference strains of species in the genus Anaerostipes were between 71.0% and 75.7%, which are below the ANI criterion for interspecies identity. The major components of cellular fatty acids were C12:0, C16:0, and C18:0. On the basis of phenotypic, phylogenetic, biochemical, chemotaxonomic, and genomic characteristics, we consider it reasonable to assign novel species status to strain AGMB03513T, for which we propose the name Anaerostipes faecalis sp. nov. The type strain AGMB03513T (=KCTC 25020T=NBRC 114896T).