Polygalacturonase and Pectin Lyase of Penicillium sclerotigenum

Penicillium sclerotigenum Yamamoto grew in synthetic liquid medium with pectic substance as sole carbon source, releasing proteins which exhibited polygalacturonase (PG; poly (1,4-α-D-galacturonide) glycohydrolase, EC 32.1.15) and pectin lyase (PL; poly (methoxygalacturonide) lyase, EC 4.2.2.10) activities. The enzymes were also present in mycelial extracts and Penicillium-infected yam tissues but were absent in healthy yam tissues. These enzymes were separated by molecular exclusion and ion exchange chromatography into three components. The molecular weight, estimated by gel filtration on Sephadex G-100, was approximately 72,000. Optimum temperature for activity of polygalacturonase and pectin lyase was 35°C. The pH optima for polygalacturonase and pectin lyase were pH 5.0 and pH 8.5, respectively.