• 文献标题:   Operational Stability, Regenerability, and Thermodynamics Studies on Biogenic Silica/Magnetite/Graphene Oxide Nanocomposite-Activated Candida rugosa Lipase
  • 文献类型:   Article
  • 作  者:   JACOB AG, WAHAB RA, MISSON M
  • 作者关键词:   graphene oxide, nanocomposite, operational stability, thermodynamic, esterification synthesi, ethyl valerate, biocatalyst characterization
  • 出版物名称:   POLYMERS
  • ISSN:  
  • 通讯作者地址:  
  • 被引频次:   4
  • DOI:   10.3390/polym13213854
  • 出版年:   2021

▎ 摘  要

Inorganic biopolymer-based nanocomposites are useful for stabilizing lipases for enhanced catalytic performance and easy separation. Herein, we report the operational stability, regenerability, and thermodynamics studies of the ternary biogenic silica/magnetite/graphene oxide nanocomposite (SiO2/Fe3O4/GO) as a support for Candida rugosa lipase (CRL). The X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), field-electron scanning electron microscopy (FESEM), vibrating sample magnetometry (VSM), and nitrogen adsorption/desorption data on the support and biocatalyst corroborated their successful fabrication. XPS revealed the Fe3O4 adopted Fe2+ and Fe3+ oxidation states, while XRD data of GO yielded a peak at 2 theta = 11.67 & DEG;, with the SiO2/Fe3O4/GO revealing a high surface area (& AP;261 m(2)/g). The fourier transform infrared (FTIR) spectra affirmed the successful fabricated supports and catalyst. The half-life and thermodynamic parameters of the superparamagnetic immobilized CRL (CRL/SiO2/Fe3O4/GO) improved over the free CRL. The microwave-regenerated CRL/SiO2/Fe3O4/GO (& AP;82%) exhibited higher catalytic activity than ultrasonic-regenerated (& AP;71%) ones. Lower activation (Ea) and higher deactivation energies (Ed) were also noted for the CRL/SiO2/Fe3O4/GO (13.87 kJ/mol, 32.32 kJ/mol) than free CRL (15.26 kJ/mol, 27.60 kJ/mol). A peak at 4.28 min in the gas chromatograph-flame ionization detection (GC-FID) chromatogram of the purified ethyl valerate supported the unique six types of 14 hydrogen atoms of the ester (CAS: 539-82-2) in the proton nuclear magnetic resonance (H-1-NMR) data. The results collectively demonstrated the suitability of SiO2/Fe3O4/GO in stabilizing CRL for improved operational stability and thermodynamics and permitted biocatalyst regenerability.