Rhodococcus agglutinans sp. nov., an actinobacterium isolated from a soil sample

A Gram-positive, aerobic, non-motile and non-spore forming strain, designated CFH S0262T, was isolated from a soil sample collected from Catba island in Halong Bay, Vietnam. A polyphasic approach was used to study the taxonomic position of this new isolate. Phylogenetic analyses based on 16S rRNA gene sequence showed that strain CFH S0262T belongs to the genus Rhodococcus and clustered with Rhodococcus soli DSD51WT, Rhodococcus hoagii NBRC 103062T, Rhodococcus defluvii CallT and Rhodococcus kunmingensis YIM 45607T (98.7, 98.5, 97.9 and 97.6 % similarities, respectively). Strain CFH S0262T could grow in the presence of NaCl (0–4 %, optimum 0–3 %), at pH 6.0–8.0 (optimum, pH 7.0) and at 10–40 °C (optimum, 28 °C). The predominant menaquinones of strain CFH S0262T were identified as MK-8 (H2) and MK-8 (H4). The major fatty acids (≥10 %) were found to be C16:0 and C18:1ω9c. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, a glycolipid and two unidentified phospholipids. The DNA G+C content was determined to be 71.4 mol%. Based on a comparative analysis of phenotypic and genotypic characteristics, in combination with low values of DNA–DNA hybridization between strain CFH S0262T and its closest neighbours, it is proposed that strain CFH S0262T represents a novel species of the genus Rhodococcus, for which the name Rhodococcus agglutinans sp. nov., is proposed, with the type strain CFH S0262T (=CCTCC AB2014297T=KCTC 39118T).