Arthrobacter mangrovi sp. nov., an actinobacterium isolated from the rhizosphere of a mangrove

A novel actinobacterium, designated HIs16-36 T , was isolated from the rhizosphere of a mangrove on Ishigaki Island, Okinawa, Japan, and its taxonomic position was investigated using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain HIs16-36 T was closely related to the members of the genus Arthrobacter . The highest 16S rRNA gene sequence similarity was observed with Arthrobacter crystallopoietes (98.5 %), followed by Arthrobacter globiformis (97.2 %). The peptidoglycan of strain HIs16-36 T was of the A4α type, with lysine as the diagnostic diamino acid. The predominant isoprenoid quinone was MK-9(H 2 ) and the major fatty acids were anteiso-C 15 : 0 and iso-C 15 : 0 . The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two glycolipids. These chemotaxonomic features corresponded to those of the genus Arthrobacter . Meanwhile, the differences in some phenotypic characteristics, along with the results of average nucleotide identity and digital DNA–DNA hybridization analyses, indicated that strain HIs16-36 T should be distinguished from the recognized species of the genus Arthrobacter . Therefore, strain HIs16-36 T represents a novel species of the genus Arthrobacter , for which the name Arthrobacter mangrovi sp. nov. is proposed. The type strain is HIs16-36 T (=NBRC 112813 T =TBRC 15750 T ).