Abstract: Carbonic anhydrase (CA) was immobilized on Fe3O4 by means of the covalent bonding and crosslinking method. The conditions of single factor, such as pH, temperature, time, shaker speed, enzyme dose, glutaraldehyde dose, and glutaraldehyde time, were studied. And then the optimum conditions and properties of immobilization CA were obtained. The results showed that the rate of enzyme activity recovery of immobilized enzyme is 66.90% under the optimum conditions. And the pH stability, operational stability, thermal stability and storage stability of immobilized CA are significantly higher than that of the free CA. Particularly, the immobilized CA could keep 62.58% relative enzyme activity after 5 times of catalytic hydrolysis with the substrate. enzyme activity after 5 times of catalytic hydrolysis with the substrate.
