Co-enzyme-free, enzymatic synthesis of aldehydes from renewable resources with a new and highly efficient alkene cleaving dioxygenase

Alkene cleaving dioxygenases (ADO), which can oxidatively cleave C[double bond, length as m-dash]C double bonds to the respective carbonyl compounds, may aid in waste stream utilization strategies by valorizing lignin-derived monomers. Here, we present 11 new ADOs and describe the characteristics of the most promising candidate <i>Map</i>ADO from <i>Moesziomyces aphidis</i>. <i>Map</i>ADO shows unprecedented reaction kinetics and a high yield without requiring co-enzymes or co-substrates other than O₂. We highlight the efficiency of <i>Map</i>ADO by preparative scale reaction in a whole cell approach from 50 mM isoeugenol to vanillin isolated in 85% yield. Furthermore, we demonstrate that <i>Map</i>ADO can be employed in a cascade reaction with a eugenol oxidase (<i>Sc</i>EUGO), enabling the use of eugenol as starting material. Moreover, we show that <i>Map</i>ADO can be used to convert ferulic acid - a major component of lignin - to vanillin <i>via</i> another cascade reaction employing a phenolic acid decarboxylase (PAD).