Study On The Immobilization Of Lipase By Polyacrylamide Nanoparticles

Polyacrylamide nano-particles vector has the characteristic of good biological compatibility, non-toxic and tastelessness and high bond strength, which can be obtained by copolymerization of cheap and available acrylamide and other monomers. The molecular chain containing reactive groups of amino has high protein compatibility which can be used as chemical modification. Therefore, polyacrylamide synthetic materials using as developing immobilization vector of lipase have good prospect.In this paper, Polyacrylamide nano-particles were used as immobilized carrier, immobilization conditions and catalytic properties in organic solvent of lipolase were investigated by covalent immobilization. Several aspects of results were obtained as follows: firstly, the monodisperse nanoparticles of P(AM-co-St) and P(AM-co-AAc) were prepared exploratly, and every effect condition was discussed in this paper. Secondly, the best immobilized conditions were at 35-36℃, 12h adsorption time and pH10.0 while P(AM-co-St) uesed as immobilization vector. The best catalyticeffects of esterification reaction catalysised by immobilized enzyme were at 55℃, molar ratio of lauric acid and lauryl alcohol was 1:2. Thirdly, based on the preparation of P(Am-co-St)-Mn(II) magnetic nanoparticles by emulsion, lipase was immobilized on this nanoparticles with covalent linkage. It was found that when diameter of nano-particles decreased the the coupled yield and activity of the immobilized Lipase was increased gradually. Mn(II) has obvious activation effect on immobilized enzyme. Last, based on the preparation of P(Am-co-AAc) microgel by dispersion precipitation polymerization, the microge was characterized by infrared spectrum and scanning electron microscope. The effect of temperature, pH,water content, substrate mole ratio and reaction time on enzyme activity was investigated. The immobilized enzyme could catalytic synthesis lauric acid lauryl alcohol compared with that of the free enzyme. The storage stability of immobilized enzyme was investigated, the activity of the immobilized Lipase has not been deactivated on the condition of 4℃deposited for 2 months.