Department of Chemical Engineering and Food Engineering, Federal University of Santa Catarina, P.O. Box 476, Florianopolis, SC, 88040-900, Brazil.
Bioprocess Biosyst Eng. 2020 Jul;43(7):1279-1286. doi: 10.1007/s00449-020-02324-6. Epub 2020 Mar 18.
In this work, the free lipase Eversa Transform 2.0 was used as a catalyst for enzymatic glycerolysis reaction in a solvent-free system. The product was evaluated by nuclear magnetic resonance (H NMR) and showed high conversion related to hydroxyl groups. In sequence, the product of the glycerolysis was used as stabilizer and biopolyol for the synthesis of poly(urea-urethane) nanoparticles (PUU NPs) aqueous dispersion by the miniemulsion polymerization technique, without the use of a further surfactant in the system. Reactions resulted in stable dispersions of PUU NPs with an average diameter of 190 nm. After, the formation of the PUU NPs in the presence of concentrated lipase Eversa Transform 2.0 was studied, aiming the lipase immobilization on the NP surface, and a stable enzymatic derivative with diameters around 231 nm was obtained. The hydrolytic enzymatic activity was determined using ρ-nitrophenyl palmitate (ρ-NPP) and the immobilization was confirmed by morphological analysis using transmission electron microscopy and fluorescence microscopy.
在这项工作中，自由脂肪酶 Eversa Transform 2.0 被用作无溶剂体系中酶促甘油解反应的催化剂。通过核磁共振（H NMR）对产物进行了评估，显示出与羟基相关的高转化率。接着，甘油解产物被用作稳定剂和生物多元醇，通过细乳液聚合技术合成了聚（脲-氨酯）纳米粒子（PUU NPs）的水分散体，体系中没有使用进一步的表面活性剂。反应得到了稳定的 PUU NPs 分散体，平均直径为 190nm。之后，研究了在浓缩脂肪酶 Eversa Transform 2.0 存在下 PUU NPs 的形成，旨在将脂肪酶固定在 NP 表面，得到了直径约为 231nm 的稳定的酶衍生物。使用对硝基苯棕榈酸酯（ρ-NPP）测定了水解酶活性，通过透射电子显微镜和荧光显微镜的形态分析证实了固定化。
