Biocatalytic zeolite membrane for the production of l-DOPA

An innovative route based on enzymatic conversion of l-tyrosine for l-DOPA production from mushroom tyrosinase immobilized on the inner surface of the zeolite membrane was developed. The role of the zeolite as free radical scavenger was also investigated. The immobilization of the tyrosinase on a zeolite membrane resulted more efficient than that performed on zeolite crystals. The possibility to regenerate the zeolite membrane by thermal treatment was successfully carried out. Tyrosinase immobilized on the zeolite membranes exhibited good performance in terms of specific activity and productivity. In particular, the specific activity of the enzyme immobilized on the zeolite membrane (1.93 μmol mg−1 min−1) was higher than the values present in the open literature.