Bienzymatic Cascade Combining a Peroxygenase with an Oxidase for the Synthesis of Aromatic Aldehydes from Benzyl Alcohols

Aromatic aldehydes are important aromatic compounds for the flavour and fragrance industry. In this study, a parallel cascade combining aryl alcohol oxidase fromPleurotus eryngii(PeAAOx) and unspecific peroxygenase from the basidiomyceteAgrocybe aegerita(AaeUPO) to convert aromatic primary alcohols into high-value aromatic aldehydes is proposed. Key influencing factors in the process of enzyme cascade catalysis, such as enzyme dosage, pH and temperature, were investigated. The universality ofPeAAOx coupled withAaeUPO cascade catalysis for the synthesis of aromatic aldehyde flavour compounds from aromatic primary alcohols was evaluated. In a partially optimised system (comprising 30 μMPeAAOx, 2 μMAaeUPO at pH 7 and 40 °C) up to 84% conversion of 50 mM veratryl alcohol into veratryl aldehyde was achieved in a self-sufficient aerobic reaction. Promising turnover numbers of 2800 and 21,000 forPeAAOx andAaeUPO, respectively, point towards practical applicability.Keywords:aromatic aldehydes;flavour compounds;cascade catalysis;PeAAOx;AaeUPO