sp. nov., a novel indole-acetic acid producing actinobacterium isolated from marine sand.

A Gram-positive, aerobic, heterotrophic, non-endospore-forming, rod-shaped and indole-acetic acid-producing strain, designated NEAU-184, was isolated from marine sand collected in Sanya, PR China, and its taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence data indicated that strain NEAU-184 should be assigned to the genus and formed a distinct branch with its closest neighbour, NBRC 106452 (99.1 %). 2,4-Diaminobutyric acid, d-alanine, d-glutamic acid and glycine were detected in cell-wall hydrolysate and glucose, rhamnose and xylose were detected in whole-cell hydrolysate. The polar lipids were found to contain diphosphatidylglycerol, glycolipid, phosphatidylglycerol and two unidentified lipids. The major menaquinone was MK-12 and the minor menaquinones were MK-13 and MK-11. The predominant fatty acids were anteiso-C, anteiso-C and iso-C. The DNA G+C content was 71.5 mol%. Furthermore, the strain could be clearly distinguished from its closely related type strains by the combination of DNA-DNA hybridization results and some phenotypic characteristics. Meanwhile, the strain has the ability to produce indole-acetic acid (0.334mg ml). Therefore, strain NEAU-184 represents a novel species of the genus , for which the name sp. nov. is proposed, with strain NEAU-184 (=CGMCC 4.7505=JCM 32546) as the type strain.