[Aspects of the biosynthesis of actinomycin C]

The protoplasts of Actinomyces sp. 26--115 producing actinomycin C were obtained by the action of lysozyme on the mycelial paste of a 48-hour microbial culture. The protoplast capacity for synthesizing actinomycin was decreased as compared to that of the intact mycelium. The transport of L-isoleucine, a precursor of actinomycin C biosynthesis in the protoplasts also decreased but this could not be the only cause of the decrease in the actinomycin biosynthesis capacity. The biosynthesis of actinomycin C by the protoplasts of Actinomycin sp. 26--115 did not require galactose and was not inhibited by glucose and exogenic actinomycin.