sp. nov., a biosurfactant-producing actinobacterium isolated from marine sediment.

A novel actinobacterium producing biosurfactant, designated OTB305, was isolated from marine sediment sampled at Otsuchi Bay, Iwate Prefecture, Japan and its taxonomic position was examined using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences exhibited that strain OTB305 was closely related to JCM 19630 (98.8 %) and DSM 42084 (98.8 %). The chemotaxonomic characteristics of strain OTB305 corresponded to those of the genus as follows: the diamino acid of the cell-wall peptidoglycan was ll-diaminopimelic acid; whole-cell hydrolysates contained glucose and lacked characteristic major sugars; the predominant isoprenoid quinones were MK-9(H) and MK-9(H); the polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unidentified phospholipid; the major cellular fatty acids were iso-C, C and C 7; and the genomic DNA G+C content was 72.83 mol%. However, genomic relatedness analysis based on the average nucleotide identity and some phenotypic characteristics revealed that strain OTB305 was distinguished from closely related species. Therefore, strain OTB305 represents a novel species of the genus , for which the name sp. nov. is proposed. The type strain is OTB305 (=NBRC 113255=TBRC 9682).