sp. nov., a novel endophytic actinomycete isolated from leaves of Oliv.

A novel Gram-stain-positive, endophytic actinobacterium, designated strain HDS5, was isolated from leaves of Oliv. collected from Changde City, Hunan Province, PR China. Strain HDS5 produced yellowish oil green substrate mycelia on Gause's synthetic medium, which also carried yellowish oil green aerial hyphae, fragmenting into rod-shaped elements with smooth surfaces. Strain HDS5 grew at pH 5.0-11.0 (optimum, pH 7), at 20-40 °C (optimum, 28 °C) and in the presence of 0-8.0% NaCl (w/v; optimum, 0-1.0 %). Whole-cell hydrolysates contained -diaminopimelic acid as the diagnostic amino acid and no diagnostic sugars. The predominant fatty acids were iso-C and C 9. The menaquinones were MK-10(H), MK-10(H) and MK-10(H). Strain HDS5 showed high 16S rRNA gene sequence similarity to DSM 43845 (99.72 %), DSM 45031 (99.31 %), JCM 11759 (99.17 %), DSM 43377 (99.11 %), KBS6 (99.11 %), DSM 45023 (99.04 %), NBRC 13360 (98.97 %), DSM 44048 (98.83 %), YIM 90022 (98.83 %) and <98.7 % similarities to other type strains. Phylogenetic analysis of 16S rRNA gene sequences and whole-genome sequences showed that strain HDS5 was closely related to DSM 43845. However, the average nucleotide identity based on blast and digital DNA-DNA hybridization values between them were determined to be 90.1 and 40.9 %, respectively, below the threshold of 95-96 and 70 % for the delineation of prokaryotic genomic species, suggesting that strain HDS5 represents a novel species. Furthermore, the morphological and physio-biochemical characteristics were sufficient to distinguish strain HDS5 from DSM 43845. Consequently, based on phenotypic and genotypic characteristics, strain HDS5 represents a new species, for which the name sp. nov. is proposed. The type strain is HDS5 (=MCCC 1K06172=JCM 34707).