Preparation And Application In Lipase Immobilization Of Three-dimensionally Ordered Macroporous Materials

Lipase （Triacylglycerol acylhydrolase, EC3.1.1.3） is an enzyme possessing an intrinsiccapacity to catalyze the cleavage of carboxy ester bonds to glycerol and fatty acids. Lipasesare widely used in pharmacy, biodiesel synthesization, and biosurfactant industry due to theircatalysis selectivity and stereoselectivity. Though lipases have various excellent properties,high price and unrecoverable problems restricted their industry application. To resolve theseproblems, researchers have prepared some immobilized lipases with different methods, ob-tained certain results. The average pore size of three-dimensional ordered macroporous（3DOM） materials are over50nm, and the periodic structures forming between the porouschannels.3DOM material, as a supporter, with a good permeability, allowing macromoleculeget through smoothly, are suitable for preparing immobilized lipase. In this paper, a modified3DOM, as a supporter, is used for preparing immobilized lipase by covalent bond.High-quality polystyrene （PS） colloidal crystal was obtained by emulsion polymerization.3DOM material was prepared by sol-gel method, while PS as template, and tetraethoxysilane（TEOS） hydrolyzation, as precursor. The highly ordered porous channels of samples and theuniform pore sizes are observed by scanning electron microscopy （SEM） and transmissionelectron microscopy （TEM）. PS colloidal crystals with the particles size from175nm to325nm are prepared by regulating styrene concentration, initiator contents, emulsifier contents,and polymerization time and polymerization temperature.3DOM-SiO₂materials with thepore size from100nm to220nm are obtained.Modified3DOM-SiO₂via amination is used as a supporter for lipase immobilization.Optimum react time, pH value and heat stability are determined as the optimizing reactioncondition for preparing immobilization lipase, in this study.Comparing with the catalytic performance of free lipase and immobilized lipase by oliveoil emulsification method, and determining the optimization condition of immobilized lipase.Results show that the immobilized lipase remains activity after reusing five times, avoidingdrawback of free lipase in application.