In this study, the factors affecting lipase adsorption onto SiO₂ nanoparticles including SiO₂ nanoparticles amounts (8, 19 and 30 mg/ml), lipase concentrations (30, 90 and 150 µg/ml), adsorption temperatures (5, 20 and 35 °C) and adsorption times (1, 12.5 and 24 hr) were optimized using central composite design. The optimal conditions were determined as a SiO₂ nanoparticles amount of 8.5 to 14 mg/ml, a lipase concentration of 106 to 116 μg/ml, an adsorption temperature of 20 °C and an adsorption time of 12.5 hr, which resulted in a specific activity and immobilization efficiency of 20,000 (U/g protein) and 60%, respectively. The lipase adsorbed under optimal conditions (SiO₂-lipase) was entrapped in a PVA/Alg hydrogel, successfully. FESEM and FTIR confirmed the two-step method of lipase immobilization. The entrapped SiO₂-lipase retained 76.5% of its initial activity after 30 days of storage at 4 °C while adsorbed and free lipase retained only 43.4% and 13.7%, respectively. SiO₂-lipase activity decreased to 34.43% after 10 cycles of use, while the entrapped SiO₂-lipase retained about 64.59% of its initial activity. Compared to free lipase, the K_m values increased and decreased for SiO₂-lipase and entrapped SiO₂-lipase, respectively. V_max value increased for both SiO₂-lipase and entrapped SiO₂-lipase.

在本研究中，影响脂肪酶吸附到 SiO ₂纳米颗粒上的因素包括 SiO ₂纳米颗粒的量（8、19 和 30 mg/ml）、脂肪酶浓度（30、90 和 150 µg/ml）、吸附温度（5、20 和 35 °C) 和吸附时间（1、12.5 和 24 小时）使用中心复合设计进行了优化。最佳条件确定为 SiO ₂纳米粒子量为 8.5 至 14 mg/ml，脂肪酶浓度为 106 至 116 μg/ml，吸附温度为 20 °C，吸附时间为 12.5 hr。活性和固定效率分别为 20,000（U/g 蛋白质）和 60%。在最佳条件下吸附的脂肪酶（SiO ₂-脂肪酶）被成功包裹在 PVA/Alg 水凝胶中。FESEM 和 FTIR 证实了脂肪酶固定的两步法。在 4°C 下储存 30 天后，夹带的 SiO _{2 -}脂肪酶保留了其初始活性的 76.5%，而吸附和游离脂肪酶分别仅保留了 43.4% 和 13.7%。使用 10 次循环后，SiO _{2 -}脂肪酶活性降低至 34.43%，而包埋的 SiO _{2 -}脂肪酶保留其初始活性的约 64.59%。与游离脂肪酶相比，SiO _{2 -}脂肪酶和包埋的SiO _{2 -}脂肪酶的K _m值分别增加和减少。SiO _{2 的}V_最大值增加-脂肪酶和包裹的SiO _{2 -}脂肪酶。