Process and kinetic characteristics of glucose oxidation catalyzed with immobilized enzyme

Abstract

The aim of this experiment was to study the efficient immobilization of glucose oxidase enzyme (GOX) on silica gel particles and thereby enhance the conversion of glucose to d-glucono-1,5-lactone using this catalyst. According to a modified method, GOX was covalently immobilized on silica gel particles with the size of 0.063–0.2 mm. Reactions were carried out in a thermostatically controlled laboratory batch reactor at temperatures of 25, 30, 35 and 40 °C, stirrer speed of 0, 150 and 300 min−1, air flow rates of 0, 10, 20 and 30 L/h and at pH values 5, 6, 7 and 8. Glucose conversion was determined by measuring the concentration of unreacted glucose with a spectrophotometer at 500 nm. We examined the effect of main process parameters on the stability and activity of the GOX and on the conversion of glucose oxidation, thus determined the optimal reaction conditions. Kinetic studies of glucose oxidation with immobilized GOX as the catalyst were performed concluding that this reaction follows the kinetics proposed by Michaelis–Menten.