Aerobic oxidation of glucose I. Enzymatic catalysis

The selective oxidation of D-glucose to D-gluconic acid was performed at atmospheric pressure, controlled pH value, and constant oxygen concentration, in the temperature range from 273.2 to 303.2 K, using Hyderase (a commercial glucose oxidase and catalase preparation). Measurements of initial rate as a function of initial gluco se concentration were interpreted by a simplified version of the already proposed reaction mechanism, having the form of a simple equation of the Michaelis-Menten type, with two kinetic parameters, i.e., k(1) referring to the reaction between glucose and oxidized enzyme, and k(c) referring to a combination of the other steps. The activation energy for k(1) was found to be 49.6 kJ mol(-1); an apparent activation energy of 26.7 kJ mol(-1) was obtained for kc. (C) 2004 Elsevier Inc. All rights reserved.