IMMOBILIZATION OF A PECTINLYASE FROM ASPERGILLUS-NIGER FOR APPLICATION IN FOOD-TECHNOLOGY

The immobilization of a commercial preparation of pectinlyase (PL, EC 4.2.2.3) derived from Aspergillus niger was studied in view of its possible application in fruit juice treatments. Pectinlyase is an enzyme that is subject to growing interest for the substitution of other pectic enzymes: e.g., polygalacturonase (EC 3.2.1.15) and pectinesterase (EC 3.1.1.11). The PL was immobilized by physical adsorption or by the formation of covalent bonds on organic (cellulose and its derivatives, XAD-amberlites) and inorganic (sulphides, gamma-alumina, and bentonite) supports. The supports that permitted an effective immobilization with good activity levels and sufficient stability under the operational conditions were found to be the acrylic resin XAD 7 activated with trichlorotriazine and, in particular, bentonite activated with glutaraldehyde.