Enhanced Catalytic Activity and Stability of Ginger Peroxidase Immobilized on Amino-Functionalized Silica-Coated Titanium Dioxide Nanocomposite: A Cost-Effective Tool for Bioremediation

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• 作者：Misha Ali ; Qayyum Husain ; Nida Alam ; Masood Ahmad
• 关键词：Ginger peroxidase ; Immobilization ; Nanocomposite ; Silica ; coated titanium dioxide ; Acid yellow 42 ; Decolorization
• 刊名：Water, Air, & Soil Pollution
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：228
• 期：1
• 全文大小：
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment, general; Water Quality/Water Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Soil Science & Conservation; Hydrogeology; Climate Change/Climate Change Impacts;
• 出版者：Springer International Publishing
• ISSN：1573-2932
• 卷排序：228

文摘

This study describes the immobilization of ginger peroxidase on amino-functionalized silica-coated titanium dioxide nanocomposite and its application in bioremediation process. A dramatic enhancement in enzyme activity was observed after immobilization on nanosupport which was evident from the effectiveness factor (η) value of 1.76. Immobilization of enzyme on nanosupport was confirmed by transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy. Immobilized peroxidase exhibited higher activity in a broad range of pH and temperature as compared to free enzyme. Also, the thermostability of peroxidase was strikingly improved upon immobilization. After six repeated uses, the immobilized peroxidase retained around 62% of its dye decolorization activity. V_max of the enzyme was changed to 35.01 μmol L−1 min−1 from 8.42 μmol L−1 min−1 after immobilization on nanocomposite, which was a fourfold increase as compared to the free enzyme. Circular dichroism spectroscopy demonstrated conformational changes in the secondary structure of the enzyme, a possible reason for the enhanced enzyme activity after immobilization. Immobilized peroxidase was highly efficient in the removal of acid yellow 42 dye in a stirred batch process, i.e., 90% of the dye was decolorized within 1.5 h as compared to the free enzyme decolorizing only 69% of the dye in the same period. Our results clearly demonstrate that this nanobioconjugate with enhanced catalytic activity, high stability, and very good reusability has remarkable potential for the treatment of aromatic pollutants present in wastewater.