Streptomyces panaciradicis sp. nov., A β-glucosidase-producing bacterium isolated from ginseng rhizoplane

Abstract

A Gram-staining-positive actinobacterium, designated strain 1MR-8T, was isolated from the rhizoplane of ginseng and its taxonomic status was determined using a polyphasic approach. The isolate formed long chains of spores that were straight, cylindrical and smooth-surfaced. Strain 1MR-8Tgrew at 10-37 °C (optimum 28 °C), whilst no growth was observed at 45 °C. The pH range for growth was 4.0-11.0 (optimum pH 6.0-8.0) and the NaCl range for growth was 0-7% (w/v) with optimum growth at 1% (w/v). Strain 1MR-8Thad cell-wall peptidoglycans based on LLdiaminopimelic acid. Glucose, mannose and ribose were the whole-cell sugars. The predominant isoprenoid quinones were MK-9 (H4), MK-9 (H6) and MK-9 (H8) and the major fatty acids were anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0and iso-C16 : 0. 16S rRNA gene sequencing studies showed that the novel strain was closely related to the type strains of Streptomyces caeruleatus GIMN4T, Streptomyces curacoi NRRL B-2901T, Streptomyces capoamus JCM 4734Tand Streptomyces coeruleorubidus NBRC 12761Twith similarities of 98.8 %. However, DNA-DNA relatedness, as well as physiological and biochemical analyses, showed that strain 1MR-8Tcould be differentiated from its closest phylogenetic relatives. It is proposed that this strain should be classified as a representative of a novel species of the genus Streptomyces, with the suggested name Streptomyces panaciradicis sp. nov. The type strain is 1MR-8T(=KACC 17632T=NBRC 109811T).