Studies of invertase immobilized on nano-magnetite in a magnetically stabilized fluidized bed reactor（MSFBR）

• Main Authors: Chu-Fang Kuo, 郭竹芳
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/41204089327631271790

碩士 === 國立雲林科技大學 === 工業化學與災害防治研究所 === 92 === Invertase is an enzyme that catalyzes the hydrolysis of sucrose to glucose and fructose. It plays an important role in sweetner field in food industry. In general，enzymes are rather expensive，hence it is advisable to immobilize enzyme so that it can be used more effectively. This research plans to use invertase as representive enzyme which will be immobilized on to the support made of magnetic nanomaterial of magnetite（Fe3O4）. Immobilization will be done by covalent bonding after the support is activated by 1,1-carbonyldiimidazole（CDI）. This method of immobilization has several advantages：（1）The method is quite simple，（2）Loss of enzyme activity is minimum，（3）Particle size can be maintained in nano scale region，（4）Enzyme can be used repeatedly，（5）Stability of enzyme can be enhanced，（6）Immobilization time is short and condition is very mild. However，when this immobilized enzyme is used in packed column，it could cause significant pressure drop. Besides，it may not be easy to separate the product from these tiny particles. To improve this enzyme reaction process，a magnetic field can be applied to the reactor which could cause those particles to rotate and oscillate. This motion can greatly improve material transfer as well as facilitating recovery of the immobilized enzyme. This study intends to pack the immobilized enzyme to the continuous reactor and then apply magnetic field, hopefully the material transfer barrier could be removed and the separation of product and enzyme can be achieved. The retained activity of the immobilized invertase was 77﹪. Kinetic parameters were determined for immobilized invertase，as well as for the free enzyme. The Km values for immobilized inertase （161 mM sucrose）were higher that of the free enzyme（145 mM），whereas Vmax values were smaller for the immobilized invertase. The optimum operational temperature was 50℃ higher for immobilized enzyme than that of the free enzyme. Thermal and storage stabilities were found to increase with immobilization.