Self‐Immobilizing Oxidoreductases for Flow Biocatalysis in Miniaturized Packed‐Bed Reactors

The industrial implementation of enzymes in flow biocatalysis microreactors is expected to be essential for the emergence of a bio‐based circular economy. Major challenges concern the efficient immobilization of delicate enzymes inside miniaturized reactors without compromising their catalytic activity. We describe the exploitation of the widely used His‐tag system in a microfluidic packed‐bed reactor that contains ketoreductase‐functionalized magnetic beads. In a continuous process, these reactors produced highly stereoselective (R)‐configured alcohols (d.r. 99:1) with an average conversion of > 90 % for more than 4 days. We believe that such miniaturized flow reactors can be of great utility for future sustainable production processes.