Modelling enzymatic oxidation of d-glucose with pyranose 2-oxidase in the presence of catalase

To evaluate the activity of a commercial pyranose 2-oxidase (P2Ox) used to catalyze the oxidation of β-d-glucose in the presence of catalase, systematically batch experiments have been carried out at 30 °C and an optimal pH = 6.5. A complex kinetic model was proposed including the main reaction (of Ping-Pong–Bi-Bi type) but also P2Ox inactivation by the hydrogen peroxide produced, and in situ H2O2 decomposition by catalase (of a generalized Yano-Koya kinetics). While the presence of catalase drastically slows down the P2Ox inactivation, a considerable decrease of the main reaction rate is observed. The estimated free enzyme rate constants match with the values reported in the literature, while turnover numbers are correlated with the catalase concentration. The model is recommended for further process developments and reactor optimization, its parameters being easily adaptable for every type of P2Ox.