Preparation Of Immobilized Enzyme Of Microspheres Carrier By Membrane Emulsification

In the process of enzyme catalytic reaction, it is more important that the free enzyme is immobilized due to it is difficult to be separated from product, can not endure extreme environment and can not be recycled. The free enzyme is immobilized not only make up the disadvantages but also save cost. However, when the enzyme is immobilized, it is necessary to select the suitable carrier. Because the structure characteristic of the carrier and the immobilization method have certain influence on the activity of the enzyme,So, it is important to select the suitable carrier and method to immobilize the enzyme.In this paper, using gelatin and silica as the carrier of immobilizing enzyme, the gelatin microspheres and gelatin/silica hybrid microspheres were prepared through the combination of SPG membrane emulsification method. Then, the YADH and CAT were immobilized with two kinds of microspheres. And the pH stability, storage stability and recycle stability of the immobilized enzyme was studied. The main research work of this paper is as follows:Firstly, the gelatin microspheres and gelatin/silica hybrid microspheres were prepared by SPG membrane emulsification method, and the particle size and morphology of the microspheres were characterized.Second, the gelatin microspheres and gelatin/silica hybrid microspheres immobilized enzyme were obtained by SPG membrane emulsification method, and the catalytic of immobilized enzyme was investigated by catalytic reaction.The experiment results show that: the optimum conditions of preparing gelatin microspheres are as follows: the dispersed phase concentration is 0.1g/mL, the volume ratio of dispersed phase and continuous phase is 1:6, the speed is 400rpm, the membrane pressure is (5-30) KPa, the concentration of Span-80 is 1.5%, the emulsification temperature is 55?. The surface of gelatin/silica hybrid microspheres was rough that the surface of gelatin microspheres coated with silica, and the content was 46.2%. The gelatin microspheres immobilized enzyme can still maintain the activity of 40% after storaging 28 days and can be used repeatedly. Besides, when pH was 6.0, the activity of gelatin/silica hybrid microspheres was highest. The gelatin/silica microspheres immobilized enzyme can still maintain the activity of 50% after storaging 21 days and keep the relative activity of 42.3% when it was recycle 7 number. The conclusion show that: The gelatin microspheres and gelatin/silica hybrid microspheres of controllable diameter and immobilized enzyme of microspheres carrier were successfully prepared by SPG membrane emulsification.