Streptomyces graminisoli sp. nov. and Streptomyces rhizophilus sp. nov., isolated from bamboo (Sasa borealis) rhizosphere soil.

Four strains of actinomycete, designated strains JR-19T, JR-12, JR-29 and JR-41T were isolated from bamboo (Sasa borealis) rhizosphere soil. Phylogenetic, morphological, chemotaxonomic and phenotypic analysis demonstrated that the four strains belong to the genus Streptomyces. Microscopic observation revealed that the four strains produced spirales spore chains with spiny surfaces. The cell-wall peptidoglycan of the four strains contained ll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates mainly contained glucose and ribose. The predominant menaquinones were MK-9 (H6) and MK-9 (H8). Phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that these strains and the members of the genus Streptomyces exhibited moderately high 16S rRNA gene sequence similarities of 98.3-99.3%, with the most closely related strains being Streptomyces shenzhenensis 172115T and Streptomyces gramineus JR-43T. Based on the phenotypic and genotypic data, the four strains are considered to represent two novel species of the genus Streptomyces, for which the names Streptomyces graminisoli sp. nov. [to accommodate strains JR-19T (type strain; =KACC 16472T=NBRC 108883T), JR-12 (=KACC 16471) and JR-29 (=KACC 16473)] and Streptomyces rhizophilus sp. nov. [for strain JR-41T (=KACC 16580T=NBRC 108885T)] are proposed.