EXTRACELLULAR POLYGALACTURONASES FROM PENICILLIUM-FREQUENTANS - SEPARATION AND REGULATORY ASPECTS

Extracellular polygalacturonase activities of Penicillium frequentans were induced by pectin and repressed, but not inactivated, by glucose. The absence of a carbohydrate source derepressed 50% of viscosity-diminishing activity and 36% of reducing-groups-releasing activity compared to production in the presence of pectin. High concentrations (30 mM and 50 mM) of D-galacturonic acid reduced only the viscosity-diminishing activity, and under these conditions the fungus grew poorly. Neither effect was observed if the mycelium had been previously induced by pectin. Polygalacturonase activities produced in the presence of pectin were separated by ion exchange chromatography. These enzymes eluted in six peaks, characterized as exopolygalacturonases I, II and III and endopolygalacturonases, I, II and III.