Zinc Oxide Nanoparticles Supported Lipase Immobilization for Biotransformation in Organic Solvents: A Facile Synthesis of Geranyl Acetate, Effect of Operative Variables and Kinetic Study
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- 作者：Vrutika Patel ; Chandani Shah ; Milind Deshpande…
- 刊名：Applied Biochemistry and Biotechnology
- 出版年：2016
- 出版时间：April 2016
- 年：2016
- 卷：178
- 期：8
- 页码：1630-1651
- 全文大小：1,023 KB
- 刊物类别：Chemistry and Materials Science
- 刊物主题：Chemistry
Biotechnology
Biochemistry - 出版者：Humana Press Inc.
- ISSN：1559-0291
- 卷排序：178
文摘
The present study describes grafting of zinc oxide (ZnO) nanoparticles with polyethyleneimine (PEI) followed by modification with glutraldehyde used as the bridge for binding the enzyme to support. The prepared nanocomposites were then characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy, utilized for synthesis of geranyl acetate in n-hexane. Among all the three prepared nanocomposites (ZnO + PEI, ZnO + PEI + SAA, ZnO + PEI + GLU), Candida rugosa lipase immobilized on ZnO-PEI-GLU was found to be best for higher ester synthesis. The operating conditions that maximized geranyl acetate resulted in the highest yield of 94 % in 6 h, molar ratio of 0.1:0.4 M (geraniol/vinyl acetate) in the presence of n-hexane as reaction medium. Various kinetic parameters such as Vmax, Ki(G), Km(G), and Km(VA) were determined using nonlinear regression analysis for order bi–bi mechanism. The kinetic study showed that reaction followed order bi–bi mechanism with inhibition by geraniol. Activation energy (Ea) was found to be lower for immobilized lipase (12.31 kJ mol−1) than crude lipase (19.04 kJ mol−1) indicating better catalytic efficiency of immobilized lipase. Immobilized biocatalyst demonstrated 2.23-fold increased catalytic activity than crude lipase and recycled 20 times. The studies revealed in this work showed a promising perspective of using low-cost nanobiocatalysts to overcome the well-known drawbacks of the chemical-catalyzed route.KeywordsGeranyl acetatePolyethyleneimineImmobilizationBiosynthesisLipase