Enzymatic reaction of ethanol and oleic acid by lipase and lignin peroxidase in rhamnolipid (RL) reversed micelles

Bao Shan(包珊)^{1, 2}, Yuan Xing-zhong(袁兴中)^{1, 2}, Peng Xin(彭馨)^{1, 2}, Zeng Guang-ming(曾光明)^{1, 2}, Wu Hai-peng(武海鹏)^{1, 2}, Wang Hou(王侯)^{1, 2}, Liu Huan(刘欢)^{1, 2}, Ma Yue-jie(马玉洁)^{1, 2}, Cui Kai-long(崔凯龙)^{1, 2}, Wu Xiu-lian(吴秀莲)^{1, 2}

(1. College of Environmental Science and Engineering, Hunan University, Changsha 410082, China;
2. Key Laboratory of Environmental Biology and Pollution Control of Ministry of Education (Hunan University), Changsha 410082, China)

Abstract:an environment friendly bio-surfactant of rhamnolipid (RL) was used as a solvent. The enzymatic reaction of oleic acid catalyzed by lipase and lignin peroxidase (lip) was evaluated. The optimum conditions of enzymatic reaction catalyzed by lipase (lip) were water to amphiphile molar ratio of 30 (20), RL of 60 (60) critical micelle concentration (CMC), pH of 7.0 (3.0) and temperature of 40 (30) °C, respectively. The change of enzyme conformation indicates that, for catalytic of lipase, water content is the most important factor of the enzymatic reaction of oleic acid, and pH for lip. With individual optimum conditions, the enzymatic efficiency of oleic acid catalyzed by lipase is higher than that by lip. In the presence of ethanol, the enzymatic reaction of oleic acid catalyzed by lipase suits Ping-Pong Bi-Bi mechanism. As an alternative to chemical reversed micelles, the RL reversed micelles are promising methods to enzymatic reaction of oleic acid.

Key words:lipase; lip; enzymatic reaction; rhamnolipid; reversed micelles; oleic acid