Lipases are enzymes that catalyze the esterification of fatty acids (FA) with glycerol. They are used in the production of monoacylglycerides (MAG) and diacylglycerides (DAG; pictured), owing to their substrate specificity with respect to MAG and DAG rather than triacylglycerides (TAG). Their application for the industrial scale synthesis of DAG-enriched oils strongly depends on the immobilization of the enzyme, as immobilized enzymes are often more robust than free enzymes, easy to recover, and can be reused in a convenient and continuous operation.
Yonghua Wang, South China University of Technology, Guangzhou, China, and colleagues tested the enzyme activity of SMG1, a novel lipase, in the immobilized state. The lipase was linked to a resin (Resin D380) by ionic bonding between the functional NH2 groups and the amino acid residues of the lipase. A high degree of esterification of 68 % was obtained and the immobilized lipase retained 49.7 % of its initial activity after being used for six times. The immobilized SMG1 also exhibits higher temperature tolerance of up to 40 °C compared to the free lipase, which could only tolerate temperatures up to 30 °C.
All these features should promote the application of enzymes in the oils and fats industry.
- Immobilization of lipase SMG1 and its application in synthesis of partial glycerides,
Weifei Wang, Yang Xu, Xiaoli Qin, Dongming Lan, Bo Yang, Yonghua Wang,
Eur. J. Lipid Sci. Technol. 2014.