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

Abstract

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, 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-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.