Alves Joana S, Garcia-Galan Cristina, Schein Mirela F, Silva Alexandre M, Barbosa Oveimar, Ayub Marco A Z, Fernandez-Lafuente Roberto, Rodrigues Rafael C
Biotechnology, Bioprocess and Biocatalysis Group, Institute of Food Science and Technology, Federal University of Rio Grande do Sul State, Av. Bento Gonçalves, 9500, P.O. Box 15090, Porto Alegre ZC 91501-970, RS, Brazil.
Department of Biocatalysis, ICP-CSIC. Campus UAM-CSIC. Cantoblanco, ZC 28049, Madrid, Spain.
Molecules. 2014 Jul 7;19(7):9562-76. doi: 10.3390/molecules19079562.
It is well established that the performance of lipase B from Candida antarctica (CALB) as catalyst for esterification reactions may be improved by the use of ultrasound technology or by its immobilization on styrene-divinylbenzene beads (MCI-CALB). The present research evaluated the synthesis of butyl acetate using MCI-CALB under ultrasonic energy, comparing the results against those obtained using the commercial preparation, Novozym 435. The optimal conditions were determined using response surface methodology (RSM) evaluating the following parameters: reaction temperature, substrate molar ratio, amount of biocatalyst, and added water. The optimal conditions for butyl acetate synthesis catalyzed by MCI-CALB were: temperature, 48.8 °C; substrate molar ratio, 3.46:1 alcohol:acid; amount of biocatalyst, 7.5%; and added water 0.28%, both as substrate mass. Under these conditions, 90% of conversion was reached in 1.5 h. In terms of operational stability, MCI-CALB was reused in seven cycles while keeping 70% of its initial activity under ultrasonic energy. The support pore size and resistance are key points for the enzyme activity and stability under mechanical stirring. The use of ultrasound improved both activity and stability because of better homogeneity and reduced mechanical stress to the immobilized system.
众所周知，南极假丝酵母脂肪酶B（CALB）作为酯化反应的催化剂，其性能可通过使用超声技术或固定在苯乙烯 - 二乙烯基苯珠粒（MCI - CALB）上得到改善。本研究评估了在超声能量下使用MCI - CALB合成乙酸丁酯的情况，并将结果与使用商业制剂诺维信435获得的结果进行比较。使用响应面法（RSM）评估以下参数来确定最佳条件：反应温度、底物摩尔比、生物催化剂用量和加水量。MCI - CALB催化合成乙酸丁酯的最佳条件为：温度48.8℃；底物摩尔比，醇：酸为3.46:1；生物催化剂用量7.5%；加水量0.28%，均以底物质量计。在这些条件下，1.5小时内转化率达到90%。在操作稳定性方面，MCI - CALB在超声能量下可重复使用七个循环，同时保持其初始活性的70%。载体孔径和阻力是机械搅拌下酶活性和稳定性的关键点。超声的使用提高了活性和稳定性，因为它具有更好的均匀性并降低了对固定化体系的机械应力。
