聚多巴胺纳米粒子固定化磷脂酶A_(1)及其在山茶油脱胶中的应用

Immobilization of phospholipase A_(1)on polydopamine nanoparticles and its application for camellia oil degumming

利用多巴胺氧化自聚合制备了聚多巴胺纳米粒子(polydopamine nanoparticles,PDANPs),并以其为载体对Lecitase Ultra进行固定化。结果表明,在酶添加量为0.15 mL/mg,固定化时间为9 h的固定化条件下,得到的酶活力回收率和蛋白固载率分别为71.2%和78.2%。对PDANPs和制备的固定化酶(PDANPs@Lecitase Ultra)进行透射电镜、傅里叶变换红外光谱和X射线光电子能谱分析,表明成功制备了纳米尺寸的PDANPs,且Lecitase Ultra已成功固定在PDANPs上。与游离的Lecitase Ultra相比,PDANPs@Lecitase Ultra的最适pH升高了1个单位,最适温度升高了5℃,热稳定性和贮藏稳定性显著增强。将PDANPs@Lecitase Ultra用于山茶油脱胶,在较优条件下脱胶油含磷量可降至5 mg/kg以内,重复脱胶10个批次后,仍能保留57.6%的活性,表明PDANPs@Lecitase Ultra有良好的油脂脱胶工业应用前景。

PDANPs(polydopamine nanoparticles)were prepared by oxidative self-polymerization of dopamine and used as a support for Lecitase Ultra immobilization.Enzyme activity recovery(71.2%)and immobilization efficiency(78.2%)were obtained with immobilization time of 9 h and enzyme dosage of 0.15 mL/mg.The characterizations of PDANPs and immobilized enzyme(PDANPs@Lecitase Ultra)by transmission electron microscopy,Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy showed that nano-sized PDANPs were prepared,and Lecitase Ultra was successfully immobilized on PDANPs.Compared with free Lecitase Ultra,the optimum pH of PDANPs@Lecitase Ultra increased by one unit,and optimum temperature was 5℃higher.In addition,the thermal stability and storage stability were significantly improved.When PDANPs@Lecitase Ultra was applied in camellia oil degumming,phosphorus content of the degummed oil can be reduced to less than 5 mg/kg under optimal conditions.In addition,PDANPs@Lecitase Ultra still retained 57.6%of initial enzyme activity after 10 cycles,indicating that PDANPs@Lecitase Ultra has a good industrial application prospect in oil degumming.