[Regulators of differentiation in Streptomyces cyaneofuscatus]

Streptomyces cyaneofuscatus PRL 1642 producing valinomycin was shown to synthesize bioregulators of differentiation similar to A factor. The regulators stimulate spore formation and streptomycin synthesis in a Streptomyces griseus 1439 mutant deficient in A factor. Some S. cyaneofuscatus mutants respond to A factor addition into the medium by an increase in valinomycin synthesis and a change in morphological properties. The regulators from S. cyaneofuscatus are more effective toward mutants of this species than toward S. griseus mutants.