反胶束漆酶/纤维素酶体系中油酸酯化的优化

Optimization of esterification of oleic acid by reversed micelle-laccase/cellulase system

漆酶和纤维素酶在反胶束水核中心具有较强的催化活性。为了对反胶束酶体系中油酸酯化反应深入研究,采用生物表面活性剂鼠李糖脂构建反胶束体系作为漆酶与纤维素酶酯化油酸的催化反应场所。通过实验研究了反胶束体系的不同条件对酯化产物含量的影响。对于反胶束漆酶体系,最佳酯化条件为:含水量W040%,鼠李糖脂临界胶束浓度20mmol·L^(-1),pH值4,温度40℃;对于反胶束纤维素酶体系,最佳酯化条件为:含水量20%,鼠李糖脂临界胶束浓度80 mmol·L^(-1),pH值4,温度30℃。综合考虑几个因素,漆酶比纤维素酶更适合应用于反胶束中油酸的酯化。研究同时采用荧光光谱法对漆酶和纤维素酶在反胶束体系中结构性能的变化进行研究,结果表明,当反胶束体系处于最佳酯化反应条件时,荧光强度最高。

Laccase and cellulase became catalytically active by entrapment in reverse micelles in organic sol- vent. In this study,rhamnolipid was employed to form reverse micelles for the esterifieation of oleic acid. Several influencing factors, including water content, pH, and temperature,were studied. The parameters that provided the highest ester content for the laccase system were determined to be W0 40% , rhamnolipid 20 mmol · L^- 1 , pH = 4, and 40 ℃. Meanwhile, the optimal parameters for the cellulase system were W0 20% , rhamnolipid 80 mmol· L^-1 ,PH = 4, and 30 ℃. Considering all these factors, laccase was a better choice for the esterification of oleic acid in reverse micelles than cellulase in terms of esterification efficiency. Fluorescence spectroscopy was used to reveal the conformational changes of laccase and cellulase. The fluorescence intensities of both systems were highest under the optimized experiment conditions.