title: Preparation of novel poly(hydroxyethyl methacrylate-co-glycidyl methacrylate)-grafted core-shell magnetic chitosan microspheres and immobilization of lactase.
abstract: Poly(hydroxyethyl methacrylate-co-glycidyl methacrylate)-grafted magnetic chitosan microspheres (HG-MCM) were prepared using reversed-phase suspension polymerization method. The HG-MCM presented a core-shell structure and regular spherical shape with poly(hydroxyethyl methacrylate-co-glycidyl methacrylate) grafted onto the chitosan layer coating the Fe3O4 cores. The average diameter of the magnetic microspheres was 10.67 μm, within a narrow size distribution of 6.6-17.4 μm. The saturation magnetization and retentivity of the magnetic microspheres were 7.0033 emu/g and 0.6273 emu/g, respectively. The application of HG-MCM in immobilization of lactase showed that the immobilized enzyme presented higher storage, pH and thermal stability compared to the free enzyme. This indicates that HG-MCM have potential applications in bio-macromolecule immobilization.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, No. 1800 Lihu Road, Wuxi 214122, China. ruijinyang@yahoo.com.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Rui-Jin
authors.initials: RJ
authors.lastname: Yang
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Qian
authors.forename: Xiao
authors.initials: X
authors.lastname: Hua
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Zhang
authors.forename: Wendy
authors.initials: W
authors.lastname: Katiyo
mesh_terms: D048271:Chitosan / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D007716:Kluyveromyces / Q000201:enzymology; D043322:Lactase / Q000378:metabolism*; D060328:Magnetic Phenomena; D008689:Methacrylates / Q000737:chemistry*; D008863:Microspheres; D010316:Particle Size; D011109:Polymethacrylic Acids / Q000737:chemistry*; D059027:Recycling; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D004800:Enzymes, Immobilized; D008689:Methacrylates; D011109:Polymethacrylic Acids; C005044:hydroxyethyl methacrylate; D048271:Chitosan; D043322:Lactase