Lipase from Thermomyces lanuginosus (TLL) was immobilized onto a novel heterofunctional support, divinyl sulfone (DVS) superparamagnetic nanoparticles (SPMNs) functionalized with polyethyleneimine (PEI). Particle size and zeta potential measurements, elemental analysis, X-ray powder diffraction, magnetic measurements, and infrared spectroscopy analysis were used to characterize the TLL preparations. At pH 10, it was possible to achieve 100 % of immobilization yield in 1 h. The immobilization pH gives TLL preparations with different stabilities; indeed the TLL preparation immobilized at pH 5.0 was the most stable during the thermal inactivation at all pH values. For the hydrolysis of racemic methyl mandelate, the nanobiocatalysts immobilized at pH 5.0 and blocked with ethylenediamine (EDA) and ethanolamine (ETA) obtained good enantioselectivities (68 % and 72 %, respectively) with high catalytic activities in the reaction medium at pH 7.0. The operational stability of the systems was evaluated in the esterification reaction of benzyl alcohol, obtaining up to 61 % conversion after the seventh reaction cycle. These results show that SPMN@PEI-DVS support is a robust strategy for the easy and rapid recovery of the nanobiocatalyst by applying a magnetic field, showing great potential for industrial applications.

中文翻译：

---

一种新的酶固定异功能支持物：用二乙烯基砜活化的 PEI 功能化的 Fe3O4 MNP。棉状嗜热丝孢菌脂肪酶固定化中的应用

来自疏毛嗜热丝孢菌 (TLL) 的脂肪酶被固定在新型异功能支持物上，即用聚乙烯亚胺 (PEI) 功能化的二乙烯基砜 (DVS) 超顺磁性纳米粒子 (SPMN)。使用粒度和 zeta 电位测量、元素分析、X 射线粉末衍射、磁性测量和红外光谱分析来表征 TLL 制剂。在 pH 值为 10 时，可以在 1 小时内实现 100% 的固定产率。固定化 pH 值使 TLL 制剂具有不同的稳定性；事实上，固定在 pH 5.0 的 TLL 制剂在所有 pH 值下的热灭活过程中最稳定。对于外消旋扁桃酸甲酯的水解，纳米生物催化剂固定在 pH 值为 5。0 和乙二胺 (EDA) 和乙醇胺 (ETA) 封闭获得了良好的对映选择性（分别为 68% 和 72%），在 pH 7.0 的反应介质中具有高催化活性。在苯甲醇的酯化反应中评估系统的运行稳定性，在第七个反应循环后获得高达 61% 的转化率。这些结果表明，SPMN@PEI-DVS 支持是一种通过施加磁场轻松快速回收纳米生物催化剂的稳健策略，显示出巨大的工业应用潜力。