Immobilized enzymatic alcohol oxidation as a versatile reaction module for multienzyme cascades

Abstract

Enzymatic alcohol oxidation (EAO) is highly attractive thanks to its efficiency, selectivity, and sustainability benefits, but it is often neglected as a catalytic tool for practical production due to the instability and non-reusability of enzymes. Herein, a non-enantioselective alcohol dehydrogenase engineered from Candida parapsilosis (Cps ADH) and a laccase from Trametes versicolor was immobilized on mesoporous silica nanoflowers (MSNs), fabricating Cps ADH@MSNs (41 U/gsupport) and laccase@MSNs (67 U/gsupport) for EAO, respectively. The structural and functional properties of the MSNs endowed the immobilized enzymes with higher stability than free enzymes, and the relative activity of the immobilized enzyme was 52% and 63%, respectively, after being reused five times. The immobilized enzymes exhibited high activity, selectivity, and complementary substrate specificity in alcohol oxidation. The optimized EAO, as a versatile cascade module, was coupled with several other enzymatic transformations for multi-enzymatic synthesis of high value-added chemicals. The chiral alcohols and amines were produced with 99% ee and 84% to 98% ee, respectively, and (R )-benzoin and 2-furoic acid were prepared with 91% yield, 99% ee and 86% yield, respectively, demonstrating the synthetic utility of the immobilized enzymes.