Abstract: Using chitosan and sodium alginate as micro-carrier material，calcium-alginate-chitosan microcapsules were prepared by an impulsive electrostatic preparation process. Enzyme activity of lipase immobilized in these microcapsules under different preparation conditions was investigated. Results indicated that the enzyme activity were mainly affected by lipase/alginate ratio and alginate mass concentration. The highest enzyme activity was found with 15 mg/mL enzyme loading and regular spherical microcapsules were obtained with 10 mg/mL alginate mass concentration. The microcapsule membrane creation was affected by both the relative molar mass and mass concentration of chitosan，through which the enzyme activity was also influenced. The pH value of chitosan solution regulated the ionization state of functional groups in both chitosan and alginate molecules，and hence the electrostatic binding in membrane generation，the enzyme protein encapsulation rate，and finally the enzyme activity. A maximum enzyme activity of 187 IU/g was achieved ultimately under preparation conditions with 15 mg/mL of lipase/alginate ratio，10 mg/mL of alginate mass concentration，50kDa of chitosan relative molar mass and 1 mg/mL of chitosan mass concentration with pH 3.0.

摘要： 针对固定化脂肪酶的研究背景，以壳聚糖、海藻酸钠为微载体制备材料，采用脉冲电场液滴工艺制备壳聚糖/海藻酸钙微胶囊。以脂肪酶为生物模型，系统考察了制备条件对载脂肪酶壳聚糖/海藻酸钙微胶囊酶活力的影响。结果表明：海藻酸钠质量浓度和酶与海藻酸钠载体配比是影响固定化酶活力的主要因素，载酶量为15 mg/mL，海藻酸钠质量浓度为10 mg/mL时载酶微胶囊酶活力最高，球形度好。通过改变壳聚糖质量浓度和相对分子质量，可以调控微胶囊膜的厚密程度进而影响固定化酶活力。成膜液pH值依次影响壳聚糖与海藻酸盐分子中官能团的电离状态、成膜反应静电络合程度、酶蛋白包封率，最终影响固定化酶活力。在载酶量为15 mg/mL，海藻酸钠质量浓度为10 mg/mL，壳聚糖相对分子质量、质量浓度和pH值依次为50 kDa、1 mg/mL和3.0的条件下，固定化酶活力为187 IU/g。