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(actinorhodin)) was measured. The highest q(actinorhodin) 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(actinorhodin) 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. (c) 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 53: 577-582, 1997.