Stabilization of Lipase in Polymerized High Internal Phase Emulsions

Abstract

Candida antarctica lipase B is stabilized in a porous, high internal phase emulsion (HIPE) of polydicyclopentadiene to enable biocatalytic waste stream upcycling. The immobilized lipase is subjected to thorough washing conditions and tested for stability in extreme environments and reusability. A porous internal microstructure is revealed through scanning electron microscopy. After preparation, lipase activity increased to 139 ± 9.7% of its original activity. After 10 cycles of reuse, immobilized lipase retains over 50% activity. Immobilized lipase retains activity after 24 h of exposure to temperatures ranging from 20 to 60 °C and pH values of 3, 7, and 10. In the most extreme environments tested, lipase retained 42.8 ± 21% relative activity after exposure to 60 °C and 49.4 ± 16% relative activity after exposure to pH 3. Polymerized HIPEs stabilize lipase and, thus, extend its working range. Further synthesis optimization has the potential to increase enzyme stability, immobilization efficiency, and uniformity. The reported hierarchical stabilization technique shows promise for use of immobilized lipase in non-ideal, industrially relevant conditions.