Expression of an heterologous gene activating actinorhodin biosynthesis inStreptomyces lividansandStreptomyces coelicolor

Production of the blue-pigmented antibiotic actinorhodin resulted in activation in the non-producer strain Streptomyces lividans, but not in the natural producer strain Streptomyces coelicolor, when transformed with an heterologous activator gene from Streptomyces fradiae. The gene encodes a 132 nucleotide-long transcript, responsible for the actinorhodin production phenotype, and thought to act as a putative antisense RNA, which has been detected in the transformed S. lividans cultures by reverse transcription followed by cyclic amplification.