Screening Platform\nfor Immobilized Biocatalysts Utilizing\nMiniature Rotating Bed Reactors

Biocatalysis has matured to become a technology widely\napplied\nin the chemical industry. There are numerous potential routes to improve\nthe performance of a biocatalytic process. Immobilizing enzymes can\nbe advantageous as it increases stability and simplifies separating\nenzymes from reaction mixtures. However, establishing a biocatalytic\nprocess based on immobilized enzymes is expensive, time-consuming,\nand labor-intensive. The reason for this is that a multitude of parameters\ninfluence the outcome of the immobilization and the performance in\nthe final process. Screening these parameters in parallel on a small\nscale is a common strategy to address these issues. However, when\nscreening immobilized enzymes with established methods such as centrifuge\ntubes, the reaction conditions differ substantially from the process\nconditions. We present a novel screening platform for immobilized\nenzymes based on magnetically driven miniature rotating bed reactors\n(MiniRBRs) to overcome this. This system unites the advantages of\nsmall scale operation with immobilizates and the application of rotating\nbed reactors, which are already established to be scalable at an industrial\nscale. As a model system, the synthesis of acetyl phosphate from glycolaldehyde\ncatalyzed by a phosphoketolase is used in this study. We were able\nto significantly increase the stability of the phosphoketolase by\nimmobilizing the phosphoketolase and using the MiniRBR system. In\naddition, the versatility of the MiniRBR will be demonstrated in terms\nof compatibility with different enzyme carrier materials, reaction\nconditions, and modes of operation.