Beneficial substrate partitioning boosts non-aqueous catalysis in de novo enzyme-alginate beads

Synthetic reactions often involve solvents incompatible with biocatalysts. Here, we encapsulate de novo heme-containing enzymes in calcium-alginate beads to facilitate heterogeneous biocatalysis in organic solvents. After encapsulation, enzymes remained structured and retained activity even when the beads are suspended in organic solvents. Carbene transferase activity, brought about by the heme cofactor, was enhanced when reactions were performed in organic solvent with alginate-encapsulated enzymes. Activity-solvent dependencies revealed that the activity boost is due to beneficial partitioning of the substrate between the beads and organic phase. Encapsulation furthermore facilitates enzyme recycling after the reaction. Alginate encapsulation opens up novel opportunities for biocatalysis in organic solvent systems, combining desired solvent properties of organic chemistry with enzymatic selectivity and proficiency.