In this study, Janus nanoparticles were prepared and used to construct Pickering emulsion as an emulsifier in presence of lipase. The results showed that Janus nanoparticles could be used to stable water phase in emulsion and the average particle size of emulsion was 60 μm. Phytosterol ester was successfully synthesized in Pickering emulsion catalytic system by using oleic acid as acyl accepter, and the phytosterol conversion reached 91.65 ± 2.07% under the following conditions: emulsifier amount of 1.0 wt%, oil-water ratio of 6:1, phytosterol concentration of 110 mmol/L, lipase dosage of 20 g/L, reaction temperature of 45 °C. Compared with biphasic catalytic system, Pickering emulsion catalytic system could enhance the catalytic efficiency and shorten the reaction time due to large interface area and short molecule diffusion distance. At the end of reaction, Janus nanoparticles could be recovered by simple centrifugation, the relative activity of lipase remained 72.89 ± 1.83% after repeated use for 6 times. Overall, this paper provides a novel and high efficiency interfacial biocatalysis technique for the synthesis of phytosteryl oleate.

中文翻译：

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Pickering乳液的构建及其在酶法合成植物甾醇油酸酯中的应用


在本研究中，制备了 Janus 纳米粒子，并在脂肪酶存在下将其用于构建 Pickering 乳液作为乳化剂。结果表明，Janus纳米粒子可以稳定乳液中的水相，乳液的平均粒径为60μm。以油酸为酰基受体，在Pickering乳液催化体系中成功合成植物甾醇酯，在乳化剂用量1.0 wt%、油水比6:1、植物甾醇浓度条件下，植物甾醇转化率达到91.65±2.07%。 110 mmol/L，脂肪酶用量20 g/L，反应温度45℃。与双相催化体系相比，Pickering乳液催化体系由于界面面积大、分子扩散距离短，可以提高催化效率，缩短反应时间。反应结束时，通过简单的离心即可回收Janus纳米粒子，重复使用6次后脂肪酶的相对活性仍保持在72.89±1.83%。总的来说，本文为植物甾醇油酸酯的合成提供了一种新颖高效的界面生物催化技术。