[Aeration conditions in the process of tetracycline biosynthesis. The role of organic acids].

The effect of the aeration conditions on the content of volatile acids in the fermentation broth was studied. It was shown that deterioration of the aeration conditions during the process of biosynthesis in both flasks and 750 1 fermentors resulted in decreased levels of the antibiotic accumulation and was accompanied by a simultaneous increase in the concentration of the volatile acids in the culture fluid. Under unfavourable aeration conditions the volatile acids present in the fermentation broth in higher concentrations than under the optimal conditions had no effect. It was shown that the volatile acid concentration may be used as a parameter for the control of the aeration conditions and as an index of normal biosynthetic process.