Abstract
SUMMARY: The genetic stability of the capacity of an improved strain of Streptomyces hygroscopicus to produce the macrolide antibiotic turimycin was investigated during long-term continuous culture. Dilution rate, growth-limiting substrate and culture temperature were varied. Certain culture conditions resulted in the stable propagation of the inoculated turimycin-producing population. Other conditions led to segregation of the initial population. Turimycin non-producing phenotypes appeared, and in each case the simultaneous loss of ability to form aerial mycelium was observed. The non-differentiating clones were found to be stable, without any reversion to the parental phenotype, indicating that a loss of genetic information probably took place.
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