[Ambiguous relationship between the rates of biomass growth and metabolic product biosynthesis under conditions of multifactorial limitation and inhibition].

Theoretical analysis of the relationship between the rates of the biomass growth mu and biosynthesis of the metabolites q was performed, when the both kinetic characteristics depended not on one, but on two and more environmental factors. Apparently similar effects of the factors on the biomass growth and biosynthesis (limiting, inhibition or combined limiting-inhibition) at different values of the kinetic equation constants were studied. Examples of different character of the effects of one or both factors on the growth and biosynthesis are discussed. In all cases it was found that relationship q (mu) was uncertain. The relationship pattern was connected with the fact, by means of which the culture growth was controlled, while the absolute values of the kinetic characteristics depended on the value of the second unchangeable factor. When relationship q (mu) was obtained by means of correlation between the experimentally found values of q and mu at accidentally changed factors of the environment, the relationship form could be anyone and not connected with any regularities of the microbiological process. Setting up an equation for mathematical description of relationship q (mu) in such cases is not correct. The only exception is the process, in which biosynthesis is directly connected with the culture growth rate.