[Macrokinetic equations of pH effect on the growth of Actinomyces aureofaciens and biosynthesis of tetracycline].

The effect of pH on the culture respiration rate at different concentrations of glucose in the medium was studied. It was found that the hydrogen ions showed their effect irrespective of the subsrate concentration in the medium. In this connection a type of macrokinetic equations of the effect of pH on the growth and antibiotic biosynthesis was chosen.

[Effect of dissolved carbon dioxide on tetracycline biosynthesis].

The paper presents data on the effect of CO2 dissolved in the fermentation broth on biosynthesis of tetracycline. It was shown that there was optimal concentration of CO2 for the tetracyline-producing organism. As a result of the experiments the ranges of the optimal concentrations within 2 to 8 ml of CO2 per 100 ml of the fermentation broth were determined.

[Regulation of tetracycline biosynthesis by controlling the growth of the producer].

Regulation of the rate growth of Act. aureofaciens in batch fermentation by maintaining the concentrations of phosphorus, ammonium nitrogen, glucose and pH values at the levels favourable for intensive growth at the beginning of the process and after accumulation of the biomass at the levels optimal for retarded growth of the organism resulted in significant prolongation of the period of intensive antibiotic production, i.e.

[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.