Flow‐Induced Microfluidic Assembly for Advanced Biocatalysis Materials

Abstract Exploring the potential of microfluidic systems, this study presents a groundbreaking approach harnessing energy in microfluidic flows within a purpose‐built microreactor, enabling precise deposition of functional biomaterials. Upon optimizing reactor dimensions and integrating it into a microfluidic system, sequentially flow‐induced deposition of DNA hydrogels and transformation into DNA‐protein hybrid materials with SpyTag/SpyCatcher technology is investigated. However, limited functionalization rates restrict its viability for targeted biocatalytic processes. Therefore, the direct deposition of a phenolic acid decarboxylase is investigated, which is efficiently deposited but shows limited biocatalytic performance due to shear‐induced denaturation. This challenge is overcome by a two‐step immobilization process, resulting in microfluidic bioreactors demonstrating initial high space‐time yields of up to 7000 g L⁻¹ d⁻¹, but whose process stability proves unsatisfactory. However, by exploiting the principle of flow‐induced deposition to immobilize recombinant E. coli cells as functional living materials overexpressing biocatalytically relevant enzymes, bioreactors are produced that show equally high space‐time yields in continuous whole‐cell catalysis which remain constant over periods of up to 10 days. The insights gained offer optimization strategies for advanced functional materials and innovative reactor systems holding promise for applications in fundamental materials science, biosensing, and scalable production of microreactors for biocatalysis and bioremediation.