Streptomyces stramineus sp. nov., a new species of the verticillate streptomycetes.

Strain NRRL 12292T, which produces the bleomycin-like antibiotics LL-BO1208 alpha and LL-BO1208 beta, forms umbels consisting of chains of smooth-surface ovoid spores that are borne on verticils on the serial mycelia, indicating that it is a member of the verticillate group of the genus Streptomyces formerly classified in the genus Streptoverticillium. This strain was compared morphologically and physiologically to 54 other verticillate Streptomyces strains. The levels of DNA relatedness between strain NRRL 12292T and 34 other verticillate Streptomyces strains, including strains representing at least 19 genetic species clusters, were also determined. Strain NRRL 12292T is morphologically and physiologically distinct from the other verticillate strains studied, particularly because of the straw yellow color of its aerial mycelia and spore mass. DNA hybridization data support the uniqueness of this strain, since the levels of DNA relatedness between NRRL 12292T and the other verticillate strains used in this study were low. Our data support designation of a new species, Streptomyces stramineus, whose type strain is NRRL 12292.