Kinetic studies on the growth of Aspergillus strains as well as constitutive and inductive polygalacturonase formation have been made in bath fermentations, without pH control. Equations describing growth and product formation of the four‐stage growth of microorganisms were applied for the first time to diauxic growth and enzyme formation of Aspergillus strains. Diauxic growth of the cultures has been found in both sucrose‐ and peetin‐containing media. Enzyme concentration in the second transient phase, calculated by the use of new equations, proved to be negligible. In the exponential and declining phases, the calculated values of mycelial and enzyme concentrations were in good agreement with the values observed. Types of classification of the product formation of Luedeking and Piret refer to the second cycle of diauxie. The types of product formation described by Kono and Asai and Luedeking and Piret are mostly in good agreement with each other. The greatest difference has been found in the case of inductive endo‐polygalacturonase formation, where the final enzyme formation could not be plotted because of the decrease (autolysis) in mycelial weight.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology