As a continuation of an ongoing study of DNA relatedness among red-spored streptomycetes, the homology between the four species comprising the Streptomyces fulvissimus phenotypic cluster (S fulvissimus, Streptomyces aureoverticillatus, Streptomyces longispororuber and Streptomyces spectabilis) and the four species comprising the Streptomyces griseoviridis phenotypic cluster (S. griseoviridis, Streptomyces chryseus, Streptomyces daghestonicus and Streptomyces murinus) was measured spectrophotometrically from C(0)t(0.5) determinations. All strains were also compared to 12 strains representing previously determined DNA-relatedness clusters in the Streptomyces lavendulae phenotypic cluster, including the type strain NRRL B-1230(T). The strains segregated into 15 cluster groups at DNA relatedness >80%, including 10 single-membered clusters. S. griseoviridis and S. daghestonicus were synonymous, as were S. chryseus and S. longispororuber. S. spectabilis exhibited species-level homology with strain NRRL B-2402, which had been received as S. lavendulae. S. aureoverticillatus exhibited significant DNA relatedness to Streptomyces flavotricini. None of the strains from the S. fulvissimus or S. griseoviridis clusters exhibited significant homology to the type strain of S. lavendulae.
