Streptomyces griseus does not sporulate when grown in a nutrient rich medium. Two mutants that sporulate in such media were isolated and characterized. The mutants sporulate at the same time as the wildtype when grown in a nutrient poor medium. The mutants and wildtype exhibit the same commitment to sporulation following a nutritional shiftdown. Six genomic DNA fragments of wildtype cells when transformed into the mutants caused these mutants to acquire the wildtype phenotype of not sporulating in rich growth media. Restriction analyses show that the six cloned DNA fragments are different. The six clones suppressed sporulation when transformed into Streptomyces coelicolor and Streptomyces lividans and secondary metabolite production was suppressed in S. coelicolor.
1995 The Society for Actinomycetes Japan