Protocell Flow Reactors for Enzyme and Whole-cell Mediated Biocatalysis.

The design and construction of continuous flow biochemical reactors comprising immobilized biocatalysts have generated great interest in the efficient synthesis of value-added chemicals. Living cells use compartmentalization and reaction-diffusion processes for spatiotemporal regulation of biocatalytic reactions and implementing these strategies into continuous flow reactors could offer new opportunities in reactor design and application. Herein, we demonstrate the fabrication of protocell-based continuous flow reactors for enzyme and whole-cell mediated biocatalysis. We employ semipermeable membranized coacervate vesicles as model protocells that spontaneously sequester enzymes or accumulate living bacteria to produce embodied microreactors capable of single- or multiple-step catalytic reactions. By packing millions of the enzyme/bacteria-containing coacervate vesicles in a glass column, we demonstrate a facile, cost-effective, and modular methodology capable of performing oxidoreductase, peroxidase and lipolytic reactions, enzyme-mediated L-DOPA synthesis and whole-cell glycolysis under continuous flow conditions. We show that the protocell-nested enzymes and bacterial cells exhibit enhanced activities and stability under deleterious operating conditions compared with their non-encapsulated counterparts. Our results provide a step towards the engineering of continuous flow reactors based on cell-like microscale agents and offer opportunities in the development of green and sustainable industrial bioprocessing. This article is protected by copyright. All rights reserved.