title: Immobilization of pectinase onto Fe3O4@SiO2-NH2 and its activity and stability.
abstract: Fe3O4 magnetic nanometer particles (MNPS) with a diameter of 30-40nm and coated by ammoniated silicon dioxides were developed by sol-gel method. The X-ray diffraction (XRD) pattern indicates that the Fe3O4 is wrapped in the amorphous SiO2, and the Fourier-transform infrared spectroscopy (FT-IR) analysis confirmed the NH2 group had been successfully introduced onto the surface of Fe3O4@SiO2 nanoparticles. The main factors related to the immobilization process of pectinase onto the magnetic support were optimized by multi-factor orthogonal experiments, and the recommended combination is that 3% glutaraldehyde (coupling agent), pH=8.0, 50°C, and cross-linking time 8h. Scanning electron microscope (SEM) and FT-IR analyses confirmed that the pectinase had been immobilized onto the surface of the amino modified nanoparticles. The storage stability and reusability of the pectinase were enhanced by the immobilization that 64.4% of the total starting activity was retrieved after 7 recycling batches and only about 21.1% of the total activity was lost after 30-day storage. For the application of the immobilized pectinase, the optimal pH and temperature were 8.5 and 55°C, respectively.
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Fang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China. Electronic address: honggao_chen@hotmail.com.
authors.forename: Honggao
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Environmental Engineering, Wuhan Textile University, Wuhan 430073, China.
authors.forename: Anqing
authors.initials: A
authors.lastname: Chen
mesh_terms: D000586:Amination; D003432:Cross-Linking Reagents / Q000737:chemistry; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D017743:Equipment Reuse; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D005976:Glutaral / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D044367:Phase Transition; D011096:Polygalacturonase / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature
chemical_list: D003432:Cross-Linking Reagents; D004800:Enzymes, Immobilized; D058185:Magnetite Nanoparticles; D012822:Silicon Dioxide; D011096:Polygalacturonase; D005976:Glutaral; D052203:Ferrosoferric Oxide
keywords: Immobilization; Magnetic nanometer particles (MNPS); Pectinase; Reusability