Effect of various nitrogen salts in beet pulp medium on polygalacturonase activity of Penicillium sp. 7/4B/EI 1 mutant.

The highest PG activity was obtained in beet pulp with (NH4)2HPO4 in amount equivalent to 0.14--0.28% N after 7 days of growth; At optimal concentration, (NH4)2HPO4 did not influence the biomass production, but increased the pH of the culture media to above 6.0. The PG was an extracellular enzyme, acting mainly on highly esterified pectin. The attack was of a random manner, characteristic for the endo-enzymes. The enzyme was active at temperature 20 degrees C--40 degrees C and pH 5.0--6.0.