Immobilization of lipase SMG1 and its application in synthesis of partial glycerides

Abstract

Production and immobilization of lipase SMG1 and its application in catalyzing the esterification of oleic acid with glycerol were investigated. Resin D380 was screened to immobilize enzyme among five types of macroporous resins, and Fourier transform IR analysis proved the ionic bonds between functional group (NH2) and the amino acid residues in protein molecules. The immobilized lipase SMG1, with lipase/support ratio of 75 mg/g resin and pH 7.0, was used to catalyze the esterification, and high esterification degree of 68.37% was obtained under the conditions of the immobilized lipase at a concentration of 7.5% (w/w, with respect to total reactants), a fatty acid/glycerol molar ratio of 1:7, and 40°C. The immobilized lipase retained 49.7% of its initial activity after being used for six times. Compared with the free lipase SMG1, the immobilized one was discovered to exhibit higher temperature tolerance (40°C for the immobilized lipase SMG1 and 30°C for the free one) in the esterification of fatty acid and glycerol. The new finding on the improved operation temperature of the immobilized lipase SMG1 will push the enzyme's application in the oils and fats industry.Practical applications: The immobilized lipase SMG1‐catalyzed process for production of partial glycerides from glycerol and oleic acid described in this study provides several advantages over conventional methods including the absence of TAG product, the repeatable utilization of catalyst, and a high purity of DAG.Research on the immobilization of lipase SMG1, which is a novel mono‐ and diacylglycerol enzyme, has been firstly investigated. Compared with the free lipase, immobilized lipase SMG1 presented enhanced thermal stability in the esterification of glycerol with fatty acid. The new finding on the improved operation temperature of immobilized lipase SMG1 will push the enzyme's application in the oils and fats industry.