Agromyces mariniharenae 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-184T, 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-184T should be assigned to the genus Agromyces and formed a distinct branch with its closest neighbour, Agromyces iriomotensis NBRC 106452T (99.1 %). 2,4- Diaminobutyric acid, o-alanine, o- 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- C17:0, anteiso-C15: 0 and iso- C16:0. 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-1). Therefore, strain NEAU-184T represents a novel species of the genus Agromyces, for which the name Agromyces mariniharenae sp. nov. is proposed, with strain NEAU-184T (=CGMCC 4.7505T=JCM 32546T) as the type strain.