Nucleotide sequences of streptomycete 16S ribosomal DNA: towards a specific identification system for streptomycetes using PCR.

To facilitate the differential identification of the genus Streptomyces, the 16S rRNA genes of 17 actinomycetes were sequenced and screened for the existence of streptomycete-specific signatures. The 16S rDNA of the Streptomyces strains and Amycolatopsis orientalis subsp. lurida exhibited 95-100% similarity, while that of the 16S rDNA of Actinoplanes utahensis showed only 88% similarity to the streptomycete 16S rDNAs. Potential genus-specific sequences were found in regions located around nucleotide positions 120, 800 and 1100. Several sets of primers derived from these characteristic regions were investigated as to their specificity in PCR-mediated amplifications. Most sets allowed selective amplification of the streptomycete rDNA sequences studied. RFLPs in the 16S rDNA permitted all strains to be distinguished.