Genetic analysis in Streptomyces chrysomallus

A circular linkage map was developed for Streptomyces chrysomallus, a producer of actinomycin C. The map order of various marker loci was deduced from matings and to a minor extent from protoplast fusions. The map strongly resembles that of Streptomyces coelicolor A3(2). The recombination frequencies were low and highly variable (from 10(-9) to 5 X 10(-6]. Plasmid pIJ303 expressed its thiostrepton resistance gene in S. chrysomallus but did not promote chromosomal transfer or induce the Ltz+ phenotype. The data provide a background of genetics for investigations of antibiotic synthesis in this strain.