The development of nanobiocatalysis via the immobilization of cellulase on composite magnetic nanomaterial for enhanced loading capacity and catalytic activity
The development of nanobiocatalysis via the immobilization of cellulase on composite magnetic nanomaterial for enhanced loading capacity and catalytic activity
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通过将纤维素酶固定在复合磁性纳米材料上以增强负载能力和催化活性来发展纳米生物催化。
DOI：
10.1016/j.ijbiomac.2018.07.176
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发表时间：
2018-11-01
影响因子：
8.2
通讯作者：
Ni, Liang
中科院分区：
文献类型：
--
作者：
Han, Juan;Luo, Peng;Ni, Liang
本研究在磁性Fe3O4上构建了4arm PEG NH2（分子量（MW）5 K或10 K）修饰的氧化石墨烯（GO），记为GO@Fe3O4@4arm PEG NH2。采用傅里叶变换红外(FTIR)、振动样品磁强计(VSM)、热重分析(TGA)、透射电子显微镜(TEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对GO@Fe3O4@4arm PEG NH2的形貌、结构和磁性能进行了详细表征。 GO@Fe3O4@4arm PEG NH2（MW 5 K和1 K）载体对纤维素酶的饱和负载能力分别为429和575 mg/g。此外，固定化纤维素酶比游离酶表现出增强的热稳定性、储存性和可重复使用性。两种固定化纤维素(MW 5 K和10 K)在70℃保存3 h后保留了初始活性的57%和60%，在室温保存30天后保留了初始活性的47%和50%。经过八次重复使用后，固定化纤维素（MW 5 K 和 10 K）分别保留了其初始活性的 40% 和 45%。实际应用中，当酶负载量为2-8 mg时，固定化纤维素酶糖化产生的葡萄糖远高于游离酶（固定化酶保持在游离酶的2.04-2.83倍），表明所制备的生物催化剂的潜力。 (C) 2018 Elsevier B.V. 保留所有权利。
In this study, graphene oxide (GO) decorated with 4arm PEG NH2 (molecular weight (MW) 5 K or 10 K) was constructed on magnetic Fe3O4, denoted as GO@Fe3O4@4arm PEG NH2. The morphology, structure and magnetic property of GO@Fe3O4@4arm PEG NH2 were characterized by Fourier transform infrared (FTIR), vibrating-sample magnetometer (VSM), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) in details. The saturation loading capacity of GO@Fe3O4@4arm PEG NH2 (MW 5 K and 1 K) carriers toward cellulase was 429 and 575 mg/g, respectively. Additionally, the immobilized cellulase had exhibited enhanced thermostability, storability and reusability than free enzyme. The two kinds of immobilized cellulose (MW 5 K and 10 K) retained 57% and 60% of its initial activity after 3 h at 70 degrees C, and retained 47% and 50% of its initial activity after 30 days' storage at room temperature. After eight times reuse, immobilized cellulose (MW 5 K and 10 K) retained 40% and 45% of its initial activity, respectively. In practical application, glucose generated by the saccharification with the immobilized cellulase was much higher than free enzyme (immobilized enzyme is kept at 2.04-2.83 times of the free enzyme), when the loading amount of enzyme was 2-8 mg, indicating the potential of the prepared biocatalyst. (C) 2018 Elsevier B.V. All rights reserved.