A versatile strategy for enzyme immobilization: Fabricating lipase/inorganic hybrid nanostructures on macroporous resins with enhanced catalytic properties

We proposed a facile and versatile strategy to prepare a novel immobilized enzyme, through fabricating Candida rugosa lipase (CRL)/inorganic hybrid nanosheets on sulfonated macroporous resins (SMRs). The lipase/Ca₃(PO₄)₂ on SMRs not only shows the high catalytic activity inheriting from lipase/Ca₃(PO₄)₂ hybrid nanostructures, but also possesses high strength and excellent operational stability endowed by protection of SMRs, which is more suitable for industrial application. The optimal immobilization conditions, the best catalytic conditions and its operational stability were systematically investigated. The observed maximum enzyme activity could reach 3176.11 ± 16.64 U/g protein under the optimal immobilized conditions, approximately 112% higher than free lipase. When the catalytic reaction was conducted in phosphate buffer (0.05 M, pH 8.0) at 60 °C, the immobilized lipase had the highest activity while the activity of the free lipase decreased sharply, which showed a remarkably increased tolerance performance compared with free lipase benefiting from the SMRs. As a biocatalyst, the immobilized lipase for batch hydrolysis of olive oil emulsion retained 81.6% activity after 10 times of recycling at pH 7.0 and 30 °C, which indicated that the well-designed carrier materials would be very valuable and meaningful in industrial enzyme catalysis.