碳酸酐酶在Fe3O4表面固定及性能分析研究

首先将羧基官能团引入纳米级Fe_3O_4表面,并用交联剂戊二醛将碳酸酐酶(carbonic anhydrase,CA)固定到Fe_3O_4上,即得到固定化酶。采用比表面积(BET)、热重分析(TG)、傅里叶红外(FTIR)、X射线衍射(XRD),扫面电镜(SEM)等手段对载体材料和固定化酶的物理化学性质进行表征对比。以对硝基苯酚乙酸酯(p-NPA)为底物,采用紫外分光光度计测定酶活。结果表明,制备的载体材料具有较大的比表面积,表面羧基化后,载体共价结合后的有机物含量达到11.24%;载体材料表面不存在C=C。采用戊二醛进行酶的固定化试验时,固定化酶活性最大可达到68.26%;且固定化酶比游离态酶具有更高的操作稳定性和贮藏稳定性。本方法有望将固定化酶应用在连续式填料塔反应器中以提高其低浓度CO_2的去除效率。

Immobilization and Characterization of Carbonic Anhydrase on Ferriferrous Oxide

Firstly carboxyl groups were introduced onto the surface of nano ferroferric oxide (Fe3O4), and then the carbonic anhydrase (CA) was immobilized onto the carrier by crosslinking reaction with glutaraldehyde, which meant the immbilized CA was obtained. The physical and chemical properties of the cairier and immobilized enzyme were characterized amd compared by specific surface area (BET), thermal gravimetric analysis (TG), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). P-nitrophenol acetate (p-NPA) was substrate to determine the activity, operation stability and storage stability of the immobilized CA by the ultraviolet spectrophotometer (UV). The results show that the carrier has a larger surface area; after carboxyl-functionalized, the organic content of the carrier can reach 11.24%; there was no C=C on the surface of the carrier. In the immobilization experiment using glutaraldehyde,the activity of immobilized enzyme could reach the maximum value: 68.26%. Besides, the immobilized CA had higher the operation stability and storage stability than that ofthe free CA. The method is expected to be applied in the continuous packed column reactor to improve the removal efficiency of CO2 under the low concentration.