Biocatalytic Foams from Microdroplet-Formulated Self-Assembling Enzymes.

Industrial biocatalysis plays an important role in the development of a sustainable economy, as enzymes can be used to synthesize an enormous range of complex molecules under environmentally friendly conditions. To further develop the field, intensive research is being conducted on process technologies for continuous flow biocatalysis in order to immobilize large quantities of enzyme biocatalysts in microstructured flow reactors under conditions that are as gentle as possible in order to realize efficient material conversions. We report here on monodisperse foams consisting almost entirely of enzymes covalently linked via SpyCatcher/SpyTag conjugation. The biocatalytic foams are readily available from recombinant enzymes via microfluidic air-in-water droplet formation, can be directly integrated into micro reactors, and can be used for biocatalytic conversions after drying. Reactors prepared by this method show surprisingly high stability and biocatalytic activity. We describe the physicochemical characterization of the new materials and show exemplary applications in biocatalysis using two-enzyme cascades for the stereoselective synthesis of chiral alcohols and the rare sugar tagatose. This article is protected by copyright. All rights reserved.