Blautia hominis sp. nov., isolated from human faeces.

ABSTRACT

A strictly anaerobic, Gram-stain-positive, non-motile and coccoid- or oval-shaped bacterium, designated strain KB1T, was isolated from a faecal sample of a patient with diverticulitis in South Korea. Degeneracies in the 16S rRNA gene sequence of strain KB1T were resolved by cloning, which yielded five different sequences with heterogeneity. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain KB1T formed a monophyletic branch with species in the genus Blautia, with highest sequence similarity to the type strain of Blautia producta (97.7-98.9 %), followed by Blautia coccoides (97.5-98.1 %). Strain KB1T was able to grow at temperatures of between 15 and 42 °C, with optimal growth at 37 °C, and in the presence of 20 % dehydrated bile. Acetic acid, succinic acid, lactic acid and fumaric acid were produced by strain KB1T from Gifu anaerobic medium broth as metabolic fermentation end-products. The major cellular fatty acids of strain KB1T were C14  0, C16  0 and C16  0 dimethyl aldehyde. The DNA G+C content was 46.3 mol%. The average nucleotide identity value between strain KB1T and the type strain of B. producta was 84.1 %. On the basis of polyphasic analysis, strain KB1T represents a novel species in the genus Blautia, for which the name Blautia hominis sp. nov. is proposed. The type strain is KB1T (=KCTC 15618T=JCM 32276T).