Sequence-Based Differentiation of Strains in the Streptomyces cyaneus Species-Group

Abstract

In an extensive numerical phenetic survey, a number<br />of blue, red and gray spored streptomycete strains<br />were grouped together as Streptomyces cyaneus<br />species-group, a taxon which encompasses strains<br />known to produce antitumor antibiotics, notably anthracyclines.<br />In the present investigation these and related<br />streptomycetes were the subject of morphological and<br />16S rRNA sequencing studies designed to clarify their<br />taxonomic relationships. It is evident from these results<br />that the Streptomyces cyaneus species-group encompasses<br />misclassified strains and members of several<br />distinct species. However, some of the red-spored<br />strains (e.g. Streptomyces janthinus ISP 5206T,<br />Streptomyces roseoviolaceus ISP 5277T and<br />Streptomyces violatus ISP 5209T) formed a distinct<br />clade. In contrast, most of the blue and gray-spored<br />strains showed much less sequence homology<br />between and with one another and were scattered<br />throughout the 16S rRNA Streptomyces tree. The<br />improved classification of this group of streptomycetes<br />provides an essential basis for establishing their industrial<br />and economical significance.<br /><br />