Nutritional regulation of differentiation and synthesis of an exocytoplasmic deoxyriboendonuclease in Streptomyces antibioticus.

Streptomyces antibioticus produces a cell-wall-located deoxyriboendonuclease (DNAase) the synthesis of which in submerged and surface cultures is related to the growth rate. DNAase synthesis always preceded aerial mycelium formation in surface cultures. Production of aerial mycelium began at the end of exponential growth or in the early stationary phase; it was absent in cultures grown on nutrient agar/glucose or in media with a high concentration of casein hydrolysate. These nutritional conditions also impaired production of the DNAase. External DNA substrates were not degraded by mycelium producing the DNAase. These observations lead us to suggest a role for the enzyme in the developmental cycle of S. antibioticus.