Adeogun Abideen Idowu, Kareeem Sarafadeen Olateju, Adebayo Oluwatobi Samson, Balogun Saka Adebayo
Chemistry Department, Federal University of Agriculture, Abeokuta, Nigeria.
Department of Microbiology, Federal University of Agriculture, Abeokuta, Nigeria.
3 Biotech. 2017 Jul;7(3):198. doi: 10.1007/s13205-017-0859-6. Epub 2017 Jun 30.
The role of enzyme engineering in biotechnology, biological and pharmaceutical process cannot be over emphasized. This study compared the adsorption of digestives enzymes; amylase, protease and lipase on to Zn-ferrite (ZnFeO). The metal ferrite was synthesized via a sol-gel technique and characterized with scanning electron microscopy (SEM), X-ray diffraction (XRD), Electron paramagnetic resonance (EPR) and Fourier transform infrared spectroscopy (FTIR). The adsorption was studied in a batch process and the data were subjected to kinetics and isotherm models. Characterization shows that the particle has a nanoporous structure, with pore sizes of about 5.4 nm and good magnetic properties. The FTIR data showed the presence of M-O bond, which is a characteristic of metal ferrites. The adsorption of the amylase, lipase and protease on ZnFeO follow first-order kinetic model with rate constants increasing with concentration. The maximum adsorption capacities as revealed by the generalized adsorption isotherms are 7.20, 42.90 and 22.24 mg g for amylase, lipase and protease, respectively, with cooperative binding. The Dubinin-Radushkevich model gave the maximum adsorption energies, E of 3.74 kJ mol for amylase, 2.01 kJ mol for lipase and 1.51 kJ mol for the protease adsorption, showing that the process is physisorption dominated. The isotherms fit the adsorption data in the order of Freundlinch > Generalized > Guggenheim-Anderson-de Boer > Tempkin isotherm > Dubinin-Radushkevich. Thermodynamic study revealed a spontaneous adsorption process with increased entropy. ZnFeO therefore, is a very good adsorbent for the purification of enzymes and can be used as a supporter for enzymatic process that required immobilization of the enzymes.
酶工程在生物技术、生物和制药过程中的作用再怎么强调也不为过。本研究比较了消化酶（淀粉酶、蛋白酶和脂肪酶）在锌铁氧体（ZnFeO）上的吸附情况。通过溶胶 - 凝胶技术合成了金属铁氧体，并用扫描电子显微镜（SEM）、X射线衍射（XRD）、电子顺磁共振（EPR）和傅里叶变换红外光谱（FTIR）对其进行了表征。采用间歇法研究吸附过程，并将数据应用于动力学和等温线模型。表征结果表明，该颗粒具有纳米多孔结构，孔径约为5.4纳米，具有良好的磁性。FTIR数据显示存在M - O键，这是金属铁氧体的特征。淀粉酶、脂肪酶和蛋白酶在ZnFeO上的吸附遵循一级动力学模型，速率常数随浓度增加。广义吸附等温线显示，淀粉酶、脂肪酶和蛋白酶的最大吸附容量分别为7.20、42.90和22.24毫克/克，存在协同结合。Dubinin - Radushkevich模型给出的淀粉酶、脂肪酶和蛋白酶吸附的最大吸附能E分别为3.74千焦/摩尔、2.01千焦/摩尔和1.51千焦/摩尔，表明该过程以物理吸附为主。等温线对吸附数据的拟合顺序为：Freundlinch＞广义＞Guggenheim - Anderson - de Boer＞Tempkin等温线＞Dubinin - Radushkevich。热力学研究表明吸附过程是自发的，且熵增加。因此，ZnFeO是一种非常好的酶纯化吸附剂，可作为需要固定化酶的酶促过程的载体。
