Rhodococcus yananensis sp. nov., a novel denitrification actinobacterium isolated from microbial fermentation bed...

An opaque, pink-coloured, gram-positive, aerobic bacteria (designated as FBM22-1^T), was isolated from microbial fermentation bed material from a pig farm in northwestern China. Optimal growth occurred at 30-37 °C, pH 7.0 and with 0.5 % NaCl (w/v). The strain had nitrification and denitrification functions. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the novel isolate belonged to the genus Rhodococcus. Strain FBM22-1^T was closely related to Rhodococcus zopfii NBRC 100606^T and Rhodococcus rhodochrous NBRC 16069^T, with 16S rRNA gene sequence similarities of 97.9 and 97.7 %, respectively. The predominant menaquinone in strain FBM22-1^T was MK-8(H₂). The cellular fatty acids consisted primarily of C_16 : 1ω7c and/or C_16 : 1 ω6c, C_16 : 0 and 10-methyl C_18 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and glycolipid. The G+C content of strain FBM22-1^T was 68.64 mol%. Based on the phenotypic, phylogenetic and chemotaxonomic characterization results, in combination with low values of digital DNA-DNA hybridization between strain FBM22-1^T and its closest neighbours, FBM22-1^T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus yananensis sp. nov. is proposed; the type strain is FBM22-1^T (=KCTC 49502^T=CCTCC AB2020275^T).