title: Preparation of core-shell magnetic polydopamine/alginate biocomposite for Candida rugosa lipase immobilization.
abstract: A flexible, biocompatible and bioadhesive enzyme immobilizing material, which was synthesized based on the covalent assembly of biomimetic polymer and oxidized polysaccharide on magnetic nanoparticles (NPs), has been developed in this feasibility study. In this work, the bio-inspired polymer, polydopamine (PDA), was used to modify the well-monodispersed Fe3O4 NPs (mPDA NPs) with a controllable thickness via a dip-coating process, then the alginate di-aldehyde (ADA) was covalently assembled on the mPDA NPs and employed as a naturally occurring linking agent for Candida rugosa lipase (CRL) immobilization. The resulting support material was characterized by means of the transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), thermogravimetry (TG) analyser, and vibrating sample magnetometer (VSM). It was verified that the prepared mPDA NPs possessed distinct core-shell structure with uniform size and high saturation magnetization. For further application, the mPDA NPs was utilized in CRL immobilizing procedures and demonstrated can facilitate improving the enzyme activities. The optimum amount of lipase was 200 mg g(-1) support, the optimal pH and temperature for the catalyse condition of the immobilized CRL was 7.0 and 40°C, respectively. Moreover, the immobilized CRL kept the high activity at 77% after 12 times of recycling for batch hydrolysis of olive oil emulsion. This magnetic bioadhesive composite with functionalized properties and adhesion strength presents a general strategy for the immobilization of macromolecules.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Hou
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000, China. Electronic address: zhuhao07@lzu.edu.cn.
authors.forename: Hao
authors.initials: H
authors.lastname: Zhu
mesh_terms: D000464:Alginates / Q000737:chemistry*; D002175:Candida / Q000737:chemistry* / Q000201:enzymology; D004655:Emulsions; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000302:isolation & purification; D052203:Ferrosoferric Oxide / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007211:Indoles / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry* / Q000302:isolation & purification; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D000069463:Olive Oil / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D000464:Alginates; D004655:Emulsions; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D006603:Hexuronic Acids; D007211:Indoles; D058185:Magnetite Nanoparticles; D000069463:Olive Oil; D011108:Polymers; C568283:polydopamine; D020723:Glucuronic Acid; D008049:Lipase; D052203:Ferrosoferric Oxide
keywords: Alginate di-aldehyde; Enzyme immobilization; Magnetic complex; Polydopamine