SiO2 monoliths with double-pore structure were synthesized with tetraethyl orthosilicate, polyethylene glycol, starch, ethanol and ammonia as the main raw materials via a sol-gel route. The effect of different content...SiO2 monoliths with double-pore structure were synthesized with tetraethyl orthosilicate, polyethylene glycol, starch, ethanol and ammonia as the main raw materials via a sol-gel route. The effect of different content of starch of the samples was studied on the mesopore structure, macropore appearance, hydrothermal stability and enzyme activity to immobilize gluczyme. The results indicate that porous blocks with mesopores of 10~12 nm and macropores of 10~30 μm can be formed by the removal of polyethylene glycol and starch after heating at 600 ℃. The minimal density of the obtained samples was 0.34 g·cm-3 and the maximal porosity was 76%. After being immersed in water at 80 ℃ for 7 d, the density, porosity and shape of N2 adsorption-desorption curves of the samples were almost unchanged, showing that the sample has a good hydrothermal stability. The initial enzyme activity of sample P2KD30 was 11 190 U, and definite enzyme activity could be maintained after five cycles.展开更多
A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde ...A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the couplingagent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and theeffects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were alsoinvestigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links andhydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recoveryof papain in the immobilization could reach 48%/～58%. In comparison with free papain, the resulting immobilized papainexhibits a remarkable thermostability and better reusability.展开更多
文摘SiO2 monoliths with double-pore structure were synthesized with tetraethyl orthosilicate, polyethylene glycol, starch, ethanol and ammonia as the main raw materials via a sol-gel route. The effect of different content of starch of the samples was studied on the mesopore structure, macropore appearance, hydrothermal stability and enzyme activity to immobilize gluczyme. The results indicate that porous blocks with mesopores of 10~12 nm and macropores of 10~30 μm can be formed by the removal of polyethylene glycol and starch after heating at 600 ℃. The minimal density of the obtained samples was 0.34 g·cm-3 and the maximal porosity was 76%. After being immersed in water at 80 ℃ for 7 d, the density, porosity and shape of N2 adsorption-desorption curves of the samples were almost unchanged, showing that the sample has a good hydrothermal stability. The initial enzyme activity of sample P2KD30 was 11 190 U, and definite enzyme activity could be maintained after five cycles.
基金This work was supported by the Lanzhou University Foundation for Middle-aged & Yonger Specialists (LD810718).
文摘A kind of macroporous bead carrier of copolymer containing monomer units of N-aminoethyl acrylamide and vinylalcohol was synthesized, i.e. the MR-AA carrier. Papain was immobilized on the carrier using glutaraldehyde as the couplingagent. The enzymatic activity of the immobilized papain was compared with free papain using casein as a substrate, and theeffects of glutaraldehyde concentration, pH, temperature, time and papain amount added on the activity recovery were alsoinvestigated. The results show that the MR-AA carrier contains reactive primary amine groups, hydrophilic amido links andhydroxyl groups, as well as macroporous structures based on its matrix (MR-AV matrix), furthermore, the activity recoveryof papain in the immobilization could reach 48%/～58%. In comparison with free papain, the resulting immobilized papainexhibits a remarkable thermostability and better reusability.
