Rhodococcus nanhaiensis sp. nov., an actinobacterium isolated from marine sediment

Abstract

In this study, two strains (SCSIO 10187T and SCSIO 10197) were isolated from a sediment sample collected from the South China Sea and characterized by using a polyphasic approach. Growth was observed at 15–35 °C (optimum 28 °C) and pH 5.0–8.0 (optimum pH 6.0). Based on 16S rRNA gene sequence analysis, the strains were identified as members of the genus Rhodococcus . Phylogenetic analysis showed that the two strains clustered together and the 16S rRNA gene sequence similarities between them and other members of the genus Rhodococcus were 93.2–97.7 %. The menaquinone type was MK-8(H2). Major cellular fatty acids were C16 : 0, C18 : 1ω9c, C17 : 0, 10-methyl C18 : 0, C18 : 0, C19 : 0 and C17 : 1ω8c. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannoside. The DNA G+C contents of strains SCSIO 10187T and SCSIO 10197 were 63.7 and 63.2 mol%, respectively. The combined genotypic and phenotypic data showed that the two strains represent a novel species of the genus Rhodococcus , for which the name Rhodococcus nanhaiensis is proposed; the type strain is SCSIO 10187T ( = DSM 45608T = CCTCC AB 2011024T), with SCSIO 10197 ( = DSM 45609 = CCTCC AB 2011025) as a reference strain.