Hyper-Performance of Immobilized Lipase with Hydrophobic Matrixes via Pickering Interfacial Catalysis in W/O Pickering Emulsions

Abstract

Pickering interfacial catalysis in Pickering emulsions offers a promising platform for heterogeneous catalytic reactions. In the present work, immobilized matrixes with tunable hydrophobicity were fabricated by grafting hydrophilic silica particles with different amounts of octadecyltrichlorosilane (ODTs). By screening the activity of corresponding immobilized lipases, hyperperformance, characterized by both hyperactivity and resistance to product inhibition, had been achieved. Specifically, the immobilized lipase exhibited approximately 4-fold higher activity than that of the free lipase and demonstrated marked resistance to product inhibition, ultimately leading to a final fatty acid concentration approximately three times that obtained with the free lipase. It demonstrates clearly that the hyperperformance of immobilized lipase originates from Pickering interfacial catalysis in W/O Pickering emulsions rather than in O/W Pickering emulsions. The underlying mechanism is attributed to the tuning positioning of lipase at the oil–water interfaces. It was further confirmed by adding Pickering particles as lipase inhibitors and examining the influence of operating parameters (Pickering particle concentration and volume ratio of oil-to-water) on the hyperactivity of immobilized lipase. The hyperperformance of immobilized lipase also provides guidance for selecting hydrophobic matrixes for lipase immobilization, as the hydrophobicity of immobilized matrixes is directly related to the adsorption of immobilized lipase at oil–water interfaces in W/O Pickering emulsions and consequently to the Pickering interfacial catalysis catalyzed by immobilized lipase.