[Theoretical analysis of the continuous two-stage process of the biosynthesis of a metabolic product].

A mathematical model for continuous biosynthesis of a metabolite in a battery of two apparatuses with ideal agitation is described and analysed. In the first apparatus of the battery it is advisable to maintain a high specific rate of culture growth for continuous accumulation of young active biomass while in the second apparatus a low growth rate is expedient which provides a change in the culture metabolism to biosynthesis of the required product. To make the continuous two-stage process efficient, it is necessary to add an extremely concentrated solution of the nutrients to the second apparatus of the battery.

[Effect of partial pressure of solute oxygen on the intensity of respiration of cultures of antibiotic producers].

It was shown possible to use feeding of hydrogen peroxide as a method for investigating the impact of dissolved oxygen concentrations on growth and development of microorganisms. The influence of pO2 on the respiration intensity was studied in penicillin- and erythromycin-producing cultures and it was found that dependence of the respiration intensity on pO2 had the form of a curve with saturation, at pO2 equal to zero the value of the culture respiration intensity being different from zero. A mathematical model accounting for the presence in the fermentation broth of microbial agglomerates with the average size depending on the agitation conditions is proposed for describing the relationships.