Effect of incubation on stabilization of lipase immobilized by epoxy resin

Objective  To study the effect of glycine incubation on the stability of lipase immobilized by LXEP-120 epoxy resin.

Method  Glycine solution was used to incubate lipase immobilized by epoxy resin for removing the residual epoxy groups. The incubation conditions were explored and optimized, and the enzymatic properties of the immobilized lipase before and after incubation were compared.

Result  The optimal incubation conditions were 2.5 mol/L and pH 7.0 glycine solution incubating for 24 h at 25 ℃. Following incubation, the immobilized lipase still retained about 60% of the original activity after treatment at 80 ℃ for 6 h, while the unincubated immobilized lipase retained only about 45% of the original activity. The optimal reaction pH (8.0) and optimal reaction temperature (45 ℃) of the immobilized lipase after incubation were the same as those of the unincubated immobilized lipase, and the pH tolerance, operation stability, and storage stability were the same as those before incubation.

Conclusion  Removing residual epoxy groups on immobilized enzyme through incubation is one necessary technical step. Glycine incubation can greatly improve the thermal stability of the immobilized lipase with little influence on reaction pH, pH stability, operation stability and storage stability.