Modelling of laccase-catalyzed l-DOPA oxidation in a microreactor

Laccase-catalyzed l-DOPA oxidation in an oxygen-saturated water solution was studied in a y-shaped microreactor at different residence times. In a given microreactor geometry, up to 87% conversions of l-DOPA were achieved at residence times below 2 min. A two-dimensional mathematical model composed of convection, diffusion, and enzyme reaction terms was developed. Enzyme kinetics was described with the double substrate Michaelis–Menten equation, where kinetic parameters from previously performed batch experiments were used. Model simulations, obtained by a non-equidistant finite differences numerical solution of a complex equation system, were proved and verified in a set of experiments performed in a microreactor. Based on the developed model, further microreactor design and process optimization are feasible.