Immobilization of L-asparaginase on genipin and divinyl sulfone cross-linked multi-walled carbon nanotubes and silica supports for acrylamide mitigation

Abstract

A recombinant L-asparaginase from Geobacillus kaustophilus was immobilized onto multi-walled carbon nanotubes and silica supports using divinyl sulfone and genipin crosslinkers. The optimal pH was determined to be 8.5 for all enzyme forms, while the optimal temperature was 55 degrees C for the free enzyme and 60 degrees C for all immobilized forms. Notably, the catalytic efficiency of GkASNase immobilized on silica via genipin was approximately 3.2fold higher than that of the free enzyme. GkASNase immobilized on silica support via divinyl sulfone exhibited a 28.9-fold enhancement in thermal stability compared to the free enzyme at 60 degrees C. The immobilized GkASNase samples retained at least 90 % of their initial activities after 5 reuses. All immobilized GkASNases achieved a 100 % reduction in acrylamide formation after 60 min treatment at 55 degrees C. These findings indeed highlight the potential of immobilized GkASNase as an efficient and sustainable solution to reduce acrylamide levels in food, particularly in heat-treated starchy foods.