[Kinetics of constitutive synthesis of polymethylgalacturonases by Penicillium digitatum as a function of the carbon source and pH].

Constitutive biosynthesis of polymethylgalacturonases by Penicillium digitatum is most active at the postexponential growth phase. Under certain conditions, the enzymes are synthesized at the constant rate which does not depend on the conditions of nutrition of the producing culture. An increase in the concentration of H+ ions at pH 3.0 changes the character of the fungal growth, prolongs the lag phase, decreases the rate of growth and increases the rate of the enzyme synthesis. The growth rate of Penicillium digitatum does not determine the rate of the enzyme synthesis. The enzyme synthesis does not depend on the conditions of the cultural growth.