Streptomyces aqsuensis sp. nov., isolated from ditch sediment in Xinjiang, China.

A novel actinobacterium, designated TRM46399, was isolated from ditch sediment in Xinjiang Province, Northwest China. Phylogenetic, physiological, chemotaxonomic and morphological analyses demonstrated that strain TRM46399 belonged to the genus Streptomyces. The strain was aerobic, Gram-stain-positive, had aerial mycelia that branched monopodially and formed chains of arthrospores. The spores were oval to cylindrical with smooth surfaces. The strain had an optimum NaCl concentration for growth of 5 % (w/v). The whole-cell sugar pattern of TRM46399 consisted of ribose, xylose, mannose and galactose. The predominant menaquinones were MK-9(H6), MK-9(H8) and MK-9(H10). The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides. Major fatty acids were iso-C16 : 0 (47.8 %), iso-C14 : 0 (13.5 %), C16 : 0 (8.9 %), anteiso-C15 : 0 (8.4 %), anteiso-C17 : 0 (4.2 %) and C17 : 0cyclo (2.7 %). The G+C content of the genomic DNA was 68.7 mol%. Comparative 16S rRNA gene sequence analysis indicated that strain TRM46399 (KY688182) was phylogenetically most closely related to Streptomyces xinghaiensis S187 (99.13 % sequence similarity); however, DNA-DNA hybridization studies between stain TRM46399 and S. xinhaiensis S187 showed only 65.32 % relatedness. Based on the evidence from this polyphasic study, strain TRM46399 represents a novel species of the genus Streptomyces, for which the name Streptomyces aqsuensis sp. nov. is proposed. The type strain is TRM46399 (=KCTC 39610 =CCTCC AA 2015009).