Production of actinorhodin by Streptomyces coelicolor A3(2) grown in chemostat culture

Streptomyces coelicolor was grown in variously limited chemostat cultures and the specific rate of extracellular actinorhodin production (q<INF>actinorhodin</INF>) was measured. The highest q<INF>actinorhodin</INF> values were observed in glucose- or ammonia-limited cultures, whereas almost no actinorhodin was produced in sulfate-, phosphate-, potassium-, or magnesium-limited cultures. The effect of the dilution rate on actinorhodin production was studied in glucose-limited cultures. It was found that q<INF>actinorhodin</INF> was highest at D = 0.06h⁻¹, which was well below the maximal D value tested (0.14 h⁻¹). This explains why, in batch cultures, actinorhodin production starts at the onset of the stationary phase. It was also found that the use of nitrilotriacetate instead of citrate as a chelating agent had a negative effect on actinorhodin production. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 577–582, 1997.