Oxidation of indole with CPO and GOx immobilized on mesoporous molecular sieves

Green chemistry and environmentally benign reaction engineering play an important role for future industrial processes. It is expected that the number of chemical reactions carried out via enzymatic catalysis will increase strongly. To achieve this aim, stable (viz. leaching and deactivation is prevented) heterogeneous biocatalysts are required. In this study, cross-linked enzyme aggregates of chloroperoxidase were grown in large-pore mesocellular foams (MCF). By changing the various synthesis parameters, the specific activity and the effective activity (viz. the enzyme activity units per mmol of adsorbed enzyme) are improved. The resulting biocatalysts composed of cross-linked chloroperoxidase and cross-linked glucose oxidase were tested in the oxidation of indole. The catalytic test under continuous operation conditions in a fixed-bed reactor confirmed that the cross-linked enzymes are less prone to leaching compared to the physically adsorbed enzymes in the pores of MCF or SBA-15.