PROPERTIES OF GLUCOSE-OXIDASE IMMOBILIZED IN GEL OF POLYVINYLALCOHOL

Glucose oxidase was immobilized both independently and together with catalase in gel of polyvinylalcohol (PVA) in the form of membranes on cotton base (CB). Temperature and pH effects on the activity of immobilized glucose oxidase preparations were studied. The latter were found to have the temperature and pH optimum of the soluble enzyme but with a larger range of action in the area of higher temperatures and pH values. The immobilized glucose oxidase was characterized by increased thermal and pH stabilities. Rate constants of thermal and pH inactivation of the free and immobilized forms of the enzyme were also determined. Calcium ions and casein were found to cause a substantial increase in the activity of immobilized preparations of glucose oxidase. Combined immobilized preparations of glucose oxidase and catalase were used for oxidation of solutions of D-glucose to D-gluconic acid carried out repeatedly for a period of four months with retention of their initial activity.