Brachybacterium subflavum sp. nov., a novel actinobacterium isolated from the foregut of grass carp

A novel actinobacterium, designated CFH 10395^T, was isolated from the foregut of grass carp (Ctenopharyngodon idella), which had been fed with ginseng extract supplement. The taxonomic position was investigated by a polyphasic approach. Cells of CFH 10395^T were Gram-staining-positive, aerobic, ovoid-shaped, non-spore-forming and non-motile. On the basis of the results of 16S rRNA gene sequence analysis, CFH 10395^T was most closely related to Brachybacterium endophyticum KCTC 49087^T, Brachybacterium squillarum JCM 16464^T and Brachybacterium paraconglomeratum JCM 17781^T (97.85%, 97.51 and 97.29% similarity, respectively). CFH 10395^T grew at 4-37 °C, pH 5.0-9.0 and in the presence of up to 10.0 % NaCl (w/v). The dominant menaquinone was MK-7. The whole-cell sugars were rhamnose, glucose, mannose and galactose. meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. The major fatty acids were anteiso-C_15 : 0, anteiso-C_17 : 0 and iso-C_16 : 0. The genome size was 3.99 Mbp with a DNA G+C content of 71.9 mol%. On the basis of the results of phylogenetic analysis, physiological properties, chemotaxonomic characteristics, low average nucleotide identity (ANI) and digital DDH (dDDH) results [ANI calculated using MUMmer (ANIm) <87 %, ANI calculated using blast (ANIb) <83 % and dDDH <23 %], it is concluded that CFH 10395^T represents a novel species of the genus Brachybacterium, for which the name Brachybacterium subflavum sp. nov., is proposed. The type strain is CFH 10395^T (=CGMCC 1.13804^T=KCTC 49235^T).