Actinophytocola oryzae gen. nov., sp. nov., isolated from the roots of Thai glutinous rice plants, a new member of the family Pseudonocardiaceae

Abstract

A novel endophytic actinomycete, strain GMKU 367T, was isolated from roots of Thai glutinous rice plants (Oryza sativa L. ‘RD6’) collected from Pathum Thani Rice Research Center, Pathum Thani province, Thailand. Strain GMKU 367T formed cylindrical spores on aerial mycelium, but sporangium-like structures and fragmentation of substrate mycelium were not observed. The cell-wall amino acids contained meso-diaminopimelic acid, alanine, glutamic acid and acetylated muramic acid. The whole-cell sugars were arabinose, galactose, mannose, rhamnose and ribose. Major fatty acids were iso-C15 : 0, iso-C16 : 0 and C16 : 0. The diagnostic menaquinone was MK-9(H4). The polar phospholipids were phosphatidylethanolamine and hydroxyphosphatidylethanolamine. The G+C content of the genomic DNA was 71.1 mol%. Phylogenetic analyses based on 16S rRNA gene sequence data indicated that strain GMKU 367T differed from members of the family Pseudonocardiaceae. On the basis of the evidence presented in this polyphasic study, it is proposed that strain GMKU 367T represents a novel species in a new genus in the family Pseudonocardiaceae, with the name Actinophytocola oryzae gen. nov., sp. nov.; the type strain of Actinophytocola oryzae is GMKU 367T (=BCC 31372T =NBRC 105245T).