Study On Catalytic Oxidation Of HMF By Fixed Galactose Oxidase

Galactose oxidase(GAO)has the advantages of wide catalytic substrate and high stereoselectivity,and is widely used in biopharmaceuticals,biosensors,preparation of sugar derivatives and chemicals.The paper studies the catalytic oxidation of 5-hydroxymethylfurfural(HMF)with GAO and catalase(CAT).An expression vector containing GAO was constructed and expressed in E.coli.The copper phosphate crystal formed by Cu2+ and PO43-was used as the inorganic carrier,and the GAO and GAO+CAT were biomimetically fixed to form a micron-sized flower-like structure.The immobilized enzyme was characterized by SEM and confocal microscopy.Confocal results showed that the enzyme was evenly distributed in the flower-like structure,indicating that the GAO and CAT co-mineralization effect is good.The elements contained in the mineralized product were qualitatively analyzed by EDS.The catalytic activity of GAO and CAT free double enzyme(free-GC)and mineralized GC@CuI against HMF was studied.The experimental results show that the catalytic efficiency of the double enzyme after mineralization is higher than that of the free double enzyme.The double enzyme immobilized can maintain high catalytic activity at higher temperatures.