| Amylase is a highly effective biological catalyst,mainly coming from the salivary glands and the pancreas of animals,plant and fungi.a-Amylase is one of amylase,which can cut off a-1,4 in large molecules such as starch,polysaccharide and oligomers and generate small molecules such as maltose and glucose.It is widely used in flour products processing,alcohol brewing,paper processing,fermentation engineering and textile,etc.But the three-dimensional structure of a-Amylase is sensitive to the change of the surrounding environment.The changes of chemical,physical and biological factors involved in environment can deprive biology catalytic activity of a-Amylase,and free a-Amylase can’ t reuse in the process of product processing.It is very difficult for a-Amylase to separate and purify hydrolyzed products,thus resulting higher cost in the production and application of a-Amylase.The immobilization technology of a-Amylase can overcome the above problems,but amylase by common enzyme carrier can only enhance the catalytic activity of immobilized amylase organisms.This paper chooses a kind of new enzyme carrier which can control temperature.Using temperature adjustment function of Fe3O4/SiO2 composite shell magnetic phase change energy storage microcapsule as enzyme carrier to immobilize α-Amylase,extending the application of phase change microcapsules in the biological field.The magnetic microcapsules with SiO2/Fe3O4 inorganic composite material of wall of the shell,can effectively prevent the phase change energy storage in leakage problems appeared in the process of molten material,and can improve the thermal conductivity of phase change energy storage material with phase change materials and reduce the degree of supercooling.The magnetic microcapsule with SiO2/Fe3O4 inorganic composite material as shell,can effectively prevent leakage problems appeared in the process of molten material of phase change energy storage,and improve the thermal conductivity of phase change energy storage material and reduce the degree of supercooling of phase change material;the good biocompatibility of SiO2 is not only beneficial to the immobilization of amylase,but also can effectively prevent the oxidation of Fe3O4.The Fe3O4 nanoparticles also possess microcapsules superparamagnetism,which is convenient for the later immobilization of a-Amylase;the phase-change temperature of phase change energy storage material of n-Docosane is 44.3℃,which is close to the optimal active temperature of the a-Amylase,so it can be used to improve the thermal stability of the a-Amylase.Using amino functional magnetic microcapsule as a-Amylase carrier,a-Amylase was immobilized on the surface of the magnetic microcapsule through covalent bonding.Through X-ray photoelectron spectroscopy(XPS),X-ray diffraction spectroscopy(XRD)and Fourier infrared spectroscopy(FT-IR)and so on,it was proved that alpha-amylase was successfully loaded onto the surface of magnetic microcapsules;thermal analysis test showed that the heat storage capacity of the carrier after the immobilization of a-Amylase was 155 J/g and the capsulation rate was 58%.Magnetometer(VSM)was used to analyze the magnetic separation performance of immobilization of a-Amylase.By comparing the free a-Amylase and immobilization of a-Amylase of SiO2/Fe3O4 composite shell,the study found that the immobilization of a-Amylase on magnetic microcapsules showed better catalytic activity,high thermal stability,resistance to storage performance and good cycle stability,which benefited from the temperature control function of phase change material in magnetic microcapsule enzyme carrier.The biocatalytic activity of a-Amylase was greatly enhanced after the immobilization of magnetic microcapsules,and it showed great potential in the field of biological application. |
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