2.5. Assay for pectinase activity
Pectinase assay was carried out by measuring reducing sugarsrelease from pectin hydrolyzation. One aliquot of sample was addedto a solution containing one aliquot of 1.0% pectin in 0.1 M citratebuffer, pH 4.5. After incubation at 45◦C for 30 min, reducing sugarswere determined by the dinitrosalicylic acid (DNS) method [20]using galacturonic acid (Fluka, USA) as a reference. The enzymaticactivity was expressed in terms of Unit (U). One unit of enzymeactivity was defined as the amount of enzyme that catalyze therelease of 1 mol of galacturonic acid per mL of culture filtrate perminute under assay conditions.