title: Preparation and characterization of tannase immobilized onto carboxyl-functionalized superparamagnetic ferroferric oxide nanoparticles.
abstract: Tannase from Aspergillus tubingensis was immobilized onto carboxyl-functionalized Fe3O4 nanoparticles (CMNPs), and conditions affecting tannase immobilization were investigated. Successful binding between CMNPs and tannase was confirmed by Fourier transform infrared spectroscopy and thermogravimetric analysis. Vibrating sample magnetometry and X-ray diffraction showed that the CMNPs and immobilized tannase exhibit distinct magnetic responses and superparamagnetic properties. Free and immobilized tannase exhibited identical optimal temperatures of 50°C and differing pH optima at 6 and 7, respectively. The thermal, pH, and storage stabilities of the immobilized tannase were superior to those of free tannase. After six cycles of catalytic hydrolysis of propyl gallate, the immobilized tannase maintained over 60% of its initial activity. The Michaelis constant (Km) of the immobilized enzyme indicated its higher affinity for substrate binding than the free enzyme.
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; The Research Center of Food Biotechnology, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China.
authors.forename: Changzheng
authors.initials: C
authors.lastname: Wu
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Xu
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; The Research Center of Food Biotechnology, Xiamen 361021, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Ni
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; The Research Center of Food Biotechnology, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China.
authors.forename: Qiuming
authors.initials: Q
authors.lastname: Yang
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; The Research Center of Food Biotechnology, Xiamen 361021, China.
authors.forename: Huinong
authors.initials: H
authors.lastname: Cai
authors.affiliation: College of Food and Biological Engineering, Jimei University, Xiamen 361021, China; Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering, Xiamen, Fujian Province 361021, China; The Research Center of Food Biotechnology, Xiamen 361021, China; Xiamen Key Laboratory of Marine Functional Food, Xiamen 361021, China. Electronic address: xxaaffeng@jmu.edu.cn.
authors.forename: Anfeng
authors.initials: A
authors.lastname: Xiao
mesh_terms: D001230:Aspergillus / Q000201:enzymology*; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D002384:Catalysis; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D005290:Ferric Compounds; D006868:Hydrolysis; D008280:Magnetics; D053758:Nanoparticles / Q000737:chemistry*; D010087:Oxides; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D004800:Enzymes, Immobilized; D005290:Ferric Compounds; D010087:Oxides; C000499:ferric oxide; D002265:Carboxylic Ester Hydrolases; C022711:tannase
keywords: Characterization; Enzyme properties; Immobilization; Magnetic nanoparticles; Tannase