Department of Chemical and Food Engineering, Federal University of Santa Catarina (UFSC), Florianópolis, SC, 88040-900, Brazil.
Bioprocess Biosyst Eng. 2021 Aug;44(8):1627-1637. doi: 10.1007/s00449-021-02545-3. Epub 2021 Mar 8.
In the current research, endoglucanase, one of the enzymes of the cellulolytic complex, was immobilized on kaolin by two different techniques, adsorption, and covalent bonding. A comparative study was conducted between free, adsorbed, and covalently immobilized endoglucanase. For the covalent bonding, the kaolin particles were functionalized with 3-aminopropyltriethoxysilane (APTES) and activated with glutaraldehyde. Immobilization by adsorption was performed using the kaolin without any treatment. Recovered activities after the endoglucanase immobilization by adsorption and covalent bonding were found to be 60 ± 2.5 and 65 ± 3.5%, respectively. The studies of optima pH and temperature, as well as thermal stability, showed that the catalytic characteristic of the enzyme was maintained after the immobilization by both adsorption and covalent bonding. Even after 8 cycles of use, the endoglucanase immobilized by the two techniques retained about 86% of its initial activity. The results showed that the adsorption was as effective as covalent bonding for the immobilization of endoglucanase on kaolin. However, the adsorption technique seems to have a greater potential for use in future studies, as it is simpler, cheaper, and faster than covalent immobilization. Therefore, in this work it was demonstrated that endoglucanases can be immobilized efficiently on kaolin through a very simple immobilization protocol, offering a promising strategy for performing repeated enzymatic hydrolysis reactions.
在当前的研究中，内切葡聚糖酶作为纤维素酶复合体系中的一种酶，通过两种不同的技术被固定在高岭土上，分别是吸附法和共价键结合法。本研究对游离酶、吸附酶和共价键结合酶进行了对比。对于共价键结合法，使用 3-氨丙基三乙氧基硅烷（APTES）对高岭土颗粒进行功能化，并使用戊二醛进行活化。吸附法的固定则使用未经任何处理的高岭土。吸附和共价键结合固定化内切葡聚糖酶后，回收的酶活性分别为 60±2.5%和 65±3.5%。最适 pH 值和温度以及热稳定性研究表明，在吸附和共价键结合两种固定化方式下，酶的催化特性都得到了保持。即使经过 8 次使用循环，两种技术固定化的内切葡聚糖酶仍保留了其初始活性的约 86%。结果表明，对于内切葡聚糖酶在高岭土上的固定化，吸附与共价键结合同样有效。然而，吸附技术似乎在未来的研究中有更大的应用潜力，因为它比共价固定化更简单、更经济、更快速。因此，在这项工作中，证明了内切葡聚糖酶可以通过非常简单的固定化方案有效地固定在高岭土上，为进行重复的酶解反应提供了一种很有前景的策略。
