[Oxygen demand of an Actinomyces rimosus culture dependent on the composition of the medium].

Consumption of oxygen by Act. rimosus depending on the medium composition was studied. It was shown that the level of dissolved oxygen in the fermentation broth decreased as the level of carbohydrates in the fermentor increased from 6 to 7.5 per cent. Under such conditions oxytetracycline biosynthesis appeared to be limited by oxygen and the maximum level of the antibiotic was not attained. A 2-fold increase in the concentration of the medium components resulted in an almost 2-fold increase of the biomass, while the potency level increased only by 54 per cent. The oxygen deficiency lowered the mycelium productivity with respect to the antibiotic biosynthesis to a greater extent that the rate of the culture growth.