Strain T13T, isolated from forest soil in Jeollabuk-do, South Korea, exhibited antibiotic production on yeast extract-malt extract-glucose (YMG) medium containing magnesium chloride as a trace mineral, and inhibited the growth of Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Staphylococcus epidermidis, Paenibacillus larvae, Escherichia coli, Candida albicans and Aspergillus niger. Growth occurred at 15-45 °C, pH 4-11 and in the presence of up to 2 % (w/v) NaCl. Biochemical analyses indicated that the predominant menaquinones produced by this strain were MK-9(H6) and MK-9(H8); small amounts of MK-10(H2) and MK-10(H4) were also detected. The polar lipid profile comprised diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine, and the cell-wall peptidoglycan contained ll-diaminopimelic acid, glutamic acid, alanine and glycine. Whole-cell hydrolysates contained glucose, galactose, ribose and rhamnose. The fatty-acid profile of strain T13T was made up predominantly of iso- and anteiso-branched fatty acids. Genetic analyses demonstrated that strain T13T is closely related to Streptomyces gramineus JR-43T (98.29 % 16S rRNA gene sequence similarity), S. graminisoli JR-19T (97.99 %), S. rhizophilus JR-41T (97.86 %), S. longwoodensis LMG 20096T (97.84 %), S. graminifolii JL-22T (97.79 %) and S. yaanensis Z4T (97.56 %), and DNA-DNA hybridization yielded relatedness values of 35.27-43.42 % when T13T was compared to related strains. The results of morphological, chemotaxonomic, phylogenetic and phenotypic analyses confirm that this strain represents a novel species of the genus Streptomyces, for which the name Streptomyces olivicoloratus sp. nov. is proposed. The type strain is T13T ( = KEMB 9005-210T = KACC 18227T = NBRC 110901T).