IMMOBILIZATION OF AN ENDOPECTINLYASE ON GAMMA-ALUMINA - STUDY OF FACTORS INFLUENCING THE BIOCATALYTIC MATRIX STABILITY

Endopectinlyase (EC 4.2.2.10) from Aspergillus japonicus was immobiliz ed on to gamma-alumina. Adsorption performed at pH 5.0 and a subsequen t cross-linking phase using 0.1% glutaraldehyde were the chosen immobi lization conditions. The comparison between the main biochemical param eters of the immobilized and free form of the enzyme showed that the i mmobilization procedure used did not affect the enzyme biochemical pro perties. The interactions between the carrier and the enzyme are essen tially secondary bonding. In fact they depend on the pH and on the pre sence of phosphate ions in the medium. A tentative chemical model of t he biocatalytic matrix thus obtained is proposed.