Synthesis and Application of Lipase Immobilized on Mussel-inspired Polymer Microspheres

In order to construct a new type of immobilized enzyme catalytic system, poly (glycidyl methacrylate) was used as a support, and was modified with dopamine/polyethyleneimine by the mussel-inspired co-deposition method. The resulted material was characterized by scanning electron microscope (SEM), energy spectroscopy (EDS), Zeta potential and Fourier transform infrared spectrometer (FT-IR), respectively. Then, the resulted material was applied for the immobilization of lipase, which was fermented via Candida parapsilosis CICC 33470. The characterization and enzymatic properties of immobilized enzyme were also investigated. The optimal immobilized conditions were the immobilization temperature of 30 ℃, the immobilization pH of 7.0, the immobilization time of 5 h and the immobilization initial enzyme acticity of 337.76 U/mL, together with the carrier addition of 0.2 g. It was indicated that the maximum enzyme activity reached 484.42±5.97 U/g-support, as the optimal reaction temperature, reaction pH and reaction time were 50 ℃, 8.0 and 10 min, respectively. In addition, the immobilized lipase exhibited excellent stability, and it kept 39.22% of original enzyme activity after eight reuse cycles. Furthermore, when the immobilized lipase was used to catalyze the esterification reaction of levulinic acid and lauryl alcohol, the conversion rate could reach 75.94%. It was illuminated that the modified poly (glycidyl methacrylate) could serve as a good support for lipase immobilization, and the results provided basic data for expanding the application areas of lipase in the future.