Immobilization of Glucose Oxidase on Eupergit C: Impact of Aeration, Kinetic and Operational Stability Studies of Free and Immobilized Enzyme

The effect of aeration on the stability of glucose oxidase in the reaction of glucose oxidation to gluconic acid was investigated by determining the operational stability decay rate constant in the process conditions. Eupergit C as a porous carrier was chosen for the enzyme immobilization. To evaluate glucose oxidase operational stability during process conditions, experiments of glucose oxidation were carried out in the repetitive batch reactor with and without continuous aeration at different aeration levels. It was found that the decay rate of the free enzyme linearly depended on the air flow rate. Immobilization of glucose oxidase on Eupergit C significantly enhanced enzyme stability at higher aeration rates. Kinetics of the free and immobilized enzyme was also determined. The mathematical model of glucose oxidation catalysed by free and immobilized glucose oxidase in the batch reactor was developed. Keywords: glucose oxidase, immobilization, oxygen mass transfer, enzyme stability, kinetics, mathematical modelling