Rhodococcus electrodiphilus sp nov., a marine electro active actinobacterium isolated from coral reef

An electrogenic bacterium was isolated from a marine coral, designated as strain JC435(T) and its taxonomic status examined by using a polyphasic approach. Results from the 16S rRNA gene sequence study showed that the isolate belonged to the genus Rhodococcus and formed a cluster with Rhodococcus ruber KCTC 9806(T) (99.5 % 16S rRNA gene sequence similarity) and Rhodococcus aetherivorans JCM 14343(T) (99.3 %), respectively Genome relatedness based on DNA-DNA hybridization to the type strains of closest-related species was less than 30 % and the triangle T-m of >7 degrees C, suggesting that strain represents a new species of the genus Rhodococcus. The major fatty acids were C-16:0, C-18:1 omega 9c, C(18:0 )10-methyl and C-16:1 omega 6c and/or C-16:1 omega 7c. The polar lipids of strain JC435(T) were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, phosphatidylinositol, three unknown phospholipids and an unknown amino lipid. The major isoprenoid quinone was MK-8(H-2), with 8% of MK-7(H-2) and 2% of MK-9(H-2) as minor components. Whole-cell hydrolysates contained meso-diaminopimelic acid, arabinose and galactose as the diagnostic diamino acid and sugars. Mycolic acids were detected. The genomic DNA G+C content of strain JC435(T) was 69.8 mol%. On the basis of phylogenetic genotypic, physiological and chemotaxonomic analysis, strain JC435(T) is considered to represent a novel species of the genus Rhodococcus for which the name Rhodococcus electrodiphilus sp. nov. is proposed. The type strain is JC435(T) (=KCTC 39856(T)=LMG 29881(T)=MCC 3659(T)).