Streptomyces zingiberis sp. nov., an endophytic actinobacterium isolated from the root tissue of montanum

An endophytic actinobacterium, designated strain PLAI 1- 29T, was isolated from the root tissue of Zingiber montanum collected from Pathum Thani province, Thailand. Strain PLAI 1- 29T was characterized using a polyphasic taxonomic approach. It typically exhibited morphological and chemotaxonomic properties of the genus Streptomyces. Strain PLAI 1- 29T produced a spiral spore chain on aerial mycelium and grew at 15-40 & DEG;C, pH 6-10 on International Streptomyces Project 2 agar. The maximum NaCl concentration for growth was 9 % (w/v). Cells of strain PLAI 1- 29T presented LL- diaminopimelic acid, arabinose, galactose and ribose. The detected phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside. The major menaquinones were MK- 9(H6) and MK- 9(H8). The major cellular fatty acids were iso-C16:0, anteiso-C15: 0 and anteiso-C17:0. The genome- based taxonomic details revealed the assignment of strain PLAI 1-29T to the genus Streptomyces and exhibited low threshold values for the delineation of a novel species by average nucleotide identity-BLAST (84.0%), average amino acid identity (80.0%) and digital DNA-DNA hybridization (27.6%) with its closest type strain, Streptomyces xinghaiensis S187T. Furthermore, several differential physiological and biochemical characteristics were detected between strain PLAI 1- 29T and the closest type strain. Based on the combined phenotypic and genomic features, strain PLAI 1-29T (=TBRC 7645T=NBRC 113170T) is considered to represent a new Streptomyces species, for which we propose the name Streptomyces zingiberis sp. nov.