Streptomyces aquilus sp. nov., a novel actinomycete isolated from a Chinese medicinal plant
Kaiqin Li, Yihui Guo, Junzhen Wang, Zhiyong Wang, Jiarong Zhao, Jian Gao
Abstract
The taxonomic position of a novel actinomycete isolate, designated strain GGCR-6 T , isolated from the healthy leaves of Xanthium sibiricum collected from the botanic garden of Hunan University of Science and Technology in Hunan province, PR China, was determined by a polyphasic approach. GGCR-6 T grew well on ISP series media and formed well-developed, branched substrate hyphae and aerial mycelium that differentiated into straight spore chains consisting of cylindrical spores with smooth surfaces. The diagnostic diamino acid was ll -diaminopimelic acid. The major menaquinones were MK-9(H 8 ), MK-9(H 2 ), MK-9 and MK-9(H 6 ). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphotidylinositol and phosphatidylinositol mannosides. The predominant fatty acids were C 16 : 1 ω9 c , iso-C 16 : 0 and C 16 : 0 . The phenotypic characteristics of GGCR-6 T indicated that it represented a member of the genus Streptomyces . Phylogenetic analysis based on the 16S rRNA gene sequence indicated that GGCR-6 T was most closely related to Streptomyces cyaneus NRRL B2296 T and Streptomyces griseoruber NRRL B1818 T . However, the digital DNA–DNA hybridization, the average nucleotide identity and the multi locus sequence analysis evolutionary distance clearly separate GGCR-6 T from the phylogenetically closely related species. Furthermore, the novel isolate was distinctly differentiated from S. cyaneus NRRL B2296 T and S. griseoruber NRRL B1818 T by morphological, physiological and biochemical characteristics. Based on these data, strain GGCR-6 T should be designated as a representative of a novel species of the genus Streptomyces , for which the name Streptomyces aquilus sp. nov. is proposed. The type strain is strain GGCR-6 T (=CICC 11055 T =JCM 33584 T ).