[Effect of orthophosphate on the growth rate and biosynthesis of tetracycline by an Actinomyces aureofaciens culture].

A low initial rate of the culture growth is an obligatory condition for intensive biosynthesis of tetracycline by Act. aureofaciens in batch fermentations. The mineral phosphorus concentration is a factor limiting the growth rate. Under conditions of model experiments, the maximum specific rate of the culture growth equaled to 0.07--0.08 hours-1 was observed in the presence of at least 40 gamma/ml of phosphorus: such a rate correlated with the mycelium productivity equaled to 0.40--0.42 gamma/mg/hour. Cultures growing at a rate of 0.02--0.03 hours-1 were most productive (4.8--4.2 gamma/mg/hour). Such a rate was attained at the phosphorus concentration of 25--30 gamma/ml.