Pectinases

Pectinases are enzymes that degrade pectin, a plant cell wall polysaccharide rich in galacturonic acid. They are produced by fungi, bacteria, yeasts, and plants and are widely used in industry to modify pectin-containing materials. The main activities are polygalacturonases, which hydrolyze internal alpha-1,4-glycosidic bonds in homogalacturonan; pectin lyases and pectate lyases, which cleave by beta-elimination; and pectinesterases, which remove methyl esters from galacturonic acid residues to enhance degradation. Endo- and exo-polygalacturonases differ in their pattern of action on the polymer. Enzymes targeting rhamnogalacturonan regions contribute to broad pectin degradation.

Industrial sources and production methods: Common producers include filamentous fungi such as Aspergillus niger and Aspergillus aculeatus, as well as Bacillus and Erwinia bacteria. Enzymes are produced by submerged fermentation and sold as preparations that may contain multiple pectin-degrading activities.

Applications: In the food industry, pectinases clarify fruit juices and wines, improve juice yield, and aid tissue softening during processing. They are also used in the pulp and paper industry, textile processing, and animal feed to aid fiber modification and nutrient availability. In biofuel production, pectinases help convert pectin-rich plant biomass to fermentable sugars. Regulatory status varies by country, but many food-grade pectinases are approved for use in processing.