Enzyme Immobilization on Stainless Steel Fleece and Its Mass Transfer Enhancement of Enzymatic Catalysis in a Rotating Packed Bed Reactor

Abstract

Rotating packed beds (RPB) facilitate the mixing of heterogeneous substrates, and promote high mass transfer efficiency in heterogeneous reactions. For the enzymatic reactions, traditional porous particles with immobilized enzymes are sensitive to the strong sheer force of the RPB, thus limiting its application. This work offers a strategy for enzyme immobilization on the surface of stainless-steel fleece, to improve the shear strength resistance of immobilized enzymes. Lipase was applied to investigate and optimize the immobilization. Finally, a fatty acid hydratase (FAH) was applied for immobilization based on the optimized method, which was further applied for evaluating its performance in RPB. The results indicated that metal immobilized enzymes resist a higher shear force than their particle-immobilized alternatives. Operating at a centrifugal force factor (β) of 30, the hydration conversion rate of 96% is achieved after 8 h, which was from nearly 38% faster than in a stirrer tank reactor (hydration yield of 60%). The metal immobilization, moreover, efficiently improved the enzyme reusability, as demonstrated by a conversion rate remaining above 90% after 15 batches. These results indicated that a metal immobilization method combined with an RPB reactor significantly increases the efficiency of enzymatic reactions.