Actinomycin Biosynthesis by Protoplasts Derived fromStreptomyces parvulus

Abstract

Conditions are described for the formation of protoplasts fromStreptomyces parvulusthat are able to synthesize actinomycin D de novo. Antibiotic synthesis by protoplasts, in contrast to that by mycelium, was sensitive to inhibition by actinomycin D and to a decrease in sucrose concentration. On the other hand, synthesis by mycelium was much more sensitive to inhibition by amino acid analogs (d-valine,cis-3-methylproline, and α-methyl-dl-tryptophan). In addition, the uptake of amino acids (l-methionine, sarcosine, andl- andd-valine) by protoplasts was significantly lower than that by mycelium. The advantages and limitations of using protoplasts for studying in vivo actinomycin synthesis are discussed.