What is the expected effect of pH on the activity of a fungal pectinase?
I actually doubt that the pectinase has such a broad pH range in which it works optimally. Searching the web I found two figures which support my doubts:





The first is from an article ("Immobilization of pectinase by adsorption on an alginate-coated chitin support") which compares the activity of native and immobilized pectinase under different conditions. The second is from the datasheet of a company which sells the enzyme. Both show an activity over 50% roughly between pH 3.5 and 5.5 but not at higher or lower pH values.