Lincomycin-Induced Secondary Metabolism in Streptomyces lividans 66 with a Mutation in the Gene Encoding the RNA Polymerase Beta Subunit.

Activating the genetic potential of Streptomyces strains to produce secondary metabolites can improve the production of useful biologically active compounds and facilitate the discovery of novel biologically active compounds. In this study, we found that Streptomyces lividans carrying the R440H mutation in rpoB, encoding the RNA polymerase beta subunit, grown in the presence of lincomycin at concentrations below the minimum inhibitory concentration (MIC) produced abundant amounts of actinorhodin and certain cryptic secondary metabolites despite culture conditions that restrict their production by the wild-type strain. The results indicate that lincomycin at concentrations below the MIC may strongly potentiate secondary metabolite production by Streptomyces strains carrying a specific rpoB mutation. In this study, we report an interesting phenomenon induced by combining the positive effects of certain rpoB mutations and concentration-dependent responses to lincomycin on secondary metabolism in S. lividans 66 and discuss the mechanisms and their applicability in exploring cryptic secondary metabolite production in streptomycetes.