Research On The Preparation Of CLA And Branched Chain Amino Acids By Immobilized Lipase

Lipase is a kind of efficient biocatalyst, which can participate in esterification, transesterification, acidolysis, alcoholysis, ammonia solution as well as the main hydrolysis reaction, and it has important application in the food industry, medicine and health care, biodiesel, detergent industry, chiral compounds and environmental protection. This paper mainly focused on the application of lipase hydrolysis, include the immobilized lipase prepared conjugated linoleic acid and free lipase prepared L-leucine through hydrolysis reaction.The preparation of conjugated linoleic acid need get conjugated linoleic acid methyl ester firstly in the industrial production,subsequent select alkaline as catalyst to hydrolysis conjugated linoleic acid methyl ester. The color of CLA is deep, easily saponification and complicated in the process, and a lot of waste water emerged after taking this method. Using immobilized lipase hydrolysis of conjugated linoleic acid methyl ester to produce CLA can be a very good solution for this problem. L-leucine is one of branched chain amino acids, if purify L-leucine of mixed amino acids, amino acids transformed its’ isobutyl ester firstly, then distilling to obtain high purity L-leucine isobutyl ester, and prepared L-leucine by chemical catalyst hydrolysis L-leucine isobutyl ester there has disadvantages of sulfuric acid as a catalyst, produce large amounts of salt and waste water in reaction proces for this method. Using lipase hydrolysis of L-leucine isobutyl esterr to produce L-leucine can solve this problem in this paper. I got the best hydrolysis process parameters of CLA and L-leucine preparation through expriments in this paper.The main results are as follows:1.Research on hydrolysis of linoleic acid methyl ester by immobilized lipase:choose A2ion exchange resin prepared immobilized lipase, and determined conjugated linoleic acid as hydrolysis of raw materials. Through the single factor experiment to determine the optimal hydrolysis process parameters were as follows:substrate concentration of conjugated linoleic acid methyl ester was20%, A2immobilized lipase amount was4%, reaction temperature was50℃and after4hours by Rotavapor with pumping vacuum (-0.090MPa～-0.095Mpa),the yield of conjugated linoleic acid was up to98.5percent.besides, A2immobilized lipase recycling can reach more than10times.2.Research on hydrolysis of L-leucine isobutyl ester by lipase:chose free lipase as the hydrolysis reaction biocatalyst. Through the single factor and orthogonal experiments to determine the optimal hydrolysis of L-leucine isobutyl ester process parameters were as follows:using Gly and NaOH buffer system to extract free lipase from A lipase powder,L-leucine solubility was added in reaction, L-leucine isobutyl ester quantity was2.0g, ester/water material ratio was1:13, reaction temperature was50℃,shaker rotate speed was170rpm, after13hours, the yield of L-leucine was up to95.23percent. Through hydrolysis of L-isoleucine isobutyl ester by using different enzymes, we found there had no hydrolysis effect.