In situ assembly of metal-organic framework film on hydrogen-bonded organic framework: An effective encapsulation carrier for α-amylase to enhance its stability

Natural α-Amylase (α-Amy) encounters limitation of poor operational stability because of its susceptibility to extreme temperature and pH. Here, in situ assembly of metal-organic framework (MOF) film on hydrogen-bonded organic framework (HOF) was reported as an effective encapsulation carrier for α-Amy to enhance its stability. α-Amy was firstly immobilized in HOF-101 through in situ encapsulation strategy. Then, by using HOF-101@α-Amy as core, ZIF-67 shell was synthesized through the assembly of Co 2 + and 2-methylimidazole, forming enzyme-MOF@HOF composite, ZIF-67@HOF-101@α-Amy (ZHA). In terms of characterization, the morphology and chemical structure of ZHA were investigated. Catalytic activities of immobilized α-Amy and free α-Amy were comparatively studied. In addition, the reusability and storage stability of ZHA were examined to confirm its enhanced stability. When applied in the liquefaction of starch derived from energy corn, ZHA efficiently reduced the viscosity of reaction system and produced a high yield of reducing sugars, demonstrating its great potential as a robust biocatalyst for industrial starch conversion in biorefineries.