A morphological and genetic mapping study of bald colony mutants of Streptomyces coelicolor.

Twelve bld mutations of Streptomyces coelicolor resulting in a lack of visible aerial mycelium were mapped genetically. The mutants were classified into three groups on the basis of colony morphology, production of antibiotics and morphology on different carbon sources. Four map locations were found for the bld genes and three of these were very near the loci of whi genes, which are also involved in differentiation. Closely linked bld mutations had similar phenotypes.