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 KB1, was isolated from a faecal sample of a patient with diverticulitis in South Korea. Degeneracies in the 16S rRNA gene sequence of strain KB1 were resolved by cloning, which yielded five different sequences with heterogeneity. Phylogenetic analysis based on the 16S rRNA gene sequences showed that strain KB1 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 KB1 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 KB1 from Gifu anaerobic medium broth as metabolic fermentation end-products. The major cellular fatty acids of strain KB1 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 KB1 and the type strain of B. producta was 84.1 %. On the basis of polyphasic analysis, strain KB1 represents a novel species in the genus Blautia, for which the name Blautia hominis sp. nov. is proposed. The type strain is KB1 (=KCTC 15618=JCM 32276).

Blautia—a new functional genus with potential probiotic properties?

“…The composition of this genus is constantly updated by adding new species and strains, but in general, the species in Blautia still form a relatively stable and coherent uniline branch. 27 According to reports, the human intestinal microbial community can be divided into three "enterotypes," namely, Bacteroides, Prevotella, and Ruminococcus, among which the Ruminococcus type is mostly driven by related groups of the order Clostridiales, Blautia, and unclassified Lachnospiraceae. 31 Blautia is widely distributed in mammalian feces and intestines.…”

Blautia intestinalis sp. nov., isolated from human feces

“…At the time of writing, the genus Blautia comprises 21 species and 15 validly published species with correct names (www.bacterio.net/Blautia.html). The validly published names are Blautia argi [4], Blautia caecimuris [5], Blautia coccoides [3, 6], Blautia faecicola [7], Blautia faecis [8], Blautia glucerasea [9], Blautia hansenii [3, 10], Blautia hominis [11], Blautia hydrogentrophica [3, 12], Blautia luti [3, 13] , Blautia obeum [14, 15], Blautia producta [3, 10], Blautia schinkii [3, 16], Blautia sterocoris [17] and Blautia wexlerae [3]. B.…”

Insights on the Evolutionary Genomics of the Blautia Genus: Potential New Species and Genetic Content Among Lineages

“…These sequenced reference strains (from both official or proposed species) were useful to give a name to each group they represented (Table 1). In one group, we found genomes from representative strains from both official and a proposed species in a same genomic species group: the proposed species "Blautia marasmi" [strain Marseille-P2377, GCF_900258535.1, (Pham et al, 2017a)] was found to be part of the same genomic species group as B. hominis [strain KB1, GCF_002270465.1, (Shin et al, 2018)]. Moreover, we also found that both B. producta and B. coccoides type strains are part of the same genomic species cluster, since their pairwise values reflected this feature.…”