In this research, lipase produced from the bacteria Pseudomonas aeruginosa was immobilized on rice husk silica-coated Fe3O4 nanoparticles. The process included the following steps: preparation of magnetic ferosoferic oxide nanoparticles (NP), coating NP with silica from rice husk ash, activation with glutaraldehyde and covalent immobilization of lipase on the support. The synthesis of the nanoparticle was followed by characterization through FT-IR, XRD, and FE-SEM. The hydrolysis kinetics (using 4-Nitrophenyl palmitate as a substrate) of the immobilized lipase followed Michaelis-Menten model with a Vmax and a Km value of 4.0 mM.s-1 and 0.63 mM, respectively. The immobilized lipase showed better tolerance to extreme temperature and pH compared to free lipase. About 60% of enzyme remained immobilized after ten cycles of reuse and 68.13% of it were stable until 49 days. Thus the silica-coated Fe3O4 nanoparticles appeared to be a potential support material for lipase immobilization applications.
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机译:在这项研究中,由铜绿假单胞菌细菌产生的脂肪酶被固定在稻壳二氧化硅包覆的Fe3O4纳米颗粒上。该过程包括以下步骤:制备磁性四氧化三铁纳米粒子(NP),用稻壳灰中的二氧化硅涂覆NP,用戊二醛活化以及将脂肪酶共价固定在载体上。纳米粒子的合成之后,通过FT-IR,XRD和FE-SEM进行表征。固定化脂肪酶的水解动力学(以棕榈酸4-硝基苯酯为底物)遵循Michaelis-Menten模型,其Vmax和Km值分别为4.0 mM.s-1和0.63 mM。与游离脂肪酶相比,固定化脂肪酶对极端温度和pH的耐受性更好。在重复使用10个循环后,约60%的酶仍保持固定状态,其中68.13%的酶稳定至49天。因此,二氧化硅涂覆的Fe 3 O 4纳米颗粒似乎是脂肪酶固定化应用的潜在载体材料。
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