| The epoxy group has a good reactivity,and the epoxy group-containing carrier can be used to immobilize the enzyme by covalent bonding with the enzyme molecule under mild conditions.Epoxy-containing carriers generally have good mechanical properties and chemical stability,however there are also problems such as low enzyme viability and poor biocompatibility.In addition,the morphology of the carrier material directly affects the catalytic activity and the stability of the immobilized enzyme,and the nanofibers have high enzyme loading,small substrate diffusion resistance and immobilized enzyme catalyzes high efficiency,easy to recover and so on.Therefore,in order to improve the enzyme viability and biocompatibility of epoxy-containing immobilized enzyme,the following two novel epoxy-containing immobilized enzyme vectors were designed and prepared by electrospinning.The enzyme was immobilized on the carrierThe preparation of carrier fibers containing epoxy groups and hydrophilic branches.The specific research contents including:(1)Preparation of poly(glycidyl methacrylate-co-methyl acrylate)-g-polyethylene glycol with epoxy groups by hydrophilic radical copolymerization Acrylic acid ester,and characterized by FT-IR,H-NMR,GPC and other structures.(2)The epoxy group-containing nanofiber membrane was prepared by electrospinning.The effect of spinning parameters on the morphology of nanofibers was investigated.The results showed that when the spinning voltage was 18kV,the spinning distance was 18cm and the spinning speed was 0.1 mL/h,the fiber morphology of the nanofiber membrane was better than that of the nanofiber membrane,and the fiber diameter was about 671nm.The mechanical properties of the nanofiber membrane were discussed.The results showed that with the increase of glycidyl methacrylate content,the mechanical properties of the fiber membrane carrier increased,the introduction of hydrophilic branched PEO,so that the carrier showed a certain degree of hydrophilicity.(3)The immobilized enzyme loading could reach 150mg/g under the optimum immobilized enzyme condition.Immobilized enzyme has good thermal stability,reusability and resistance to organic solvents:at 70 ? for 3h,its activity can maintain 81%;immobilized enzyme reused 5 times,the residual activity was 45%;in the organic solvent In the storage of 12h,it still maintained 70%of the relative vitality.The preparation of carriers containing epoxy groups and feather peptide.The research contents include:(1)Preparation of epoxy-containing,feather peptide composite nanofiber membrane enzyme carrier by electrospinning.When the content of feather polypeptide was 3.0%,the fiber morphology of nanofiber membrane was better,the fiber diameter was about 631 nm,and the breaking strength of carrier was 31.94 MPa.(2)The optimum amount of enzyme was 89mg/g.Equally,the immobilization of the enzyme,lipase thermal stability,reusability has been improved significantly:at 70 ? for 3h,its activity remained 79%,while the free enzyme is only 15%,immobilized enzyme repeated 7 Times,the residual activity was 62%.At the same time,the immobilized enzyme has good resistance to organic solvent,and after storage for 12h in the organic solvent,it still has 74%relative activity.This paper also explored the application of immobilized lipase in organic synthesis in order to realize the industrial value of epoxy-containing immobilized enzyme.The immobilized lipase-catalyzed organic synthesis was confirmed by the analysis of the product by NMR.The stability of the immobilized lipase catalyzed organic synthesis was demonstrated by the optimization of the catalytic conditions.The results showed that the immobilized lipase can maintain a high catalytic activity,the product conversion rate can reach 88%. |
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