Electrospun Polyethersulfone Nanofibers: A Novel Matrix for Alpha-Amylase Immobilization

  Amylases are used in various industries, mainly, starch processing that hydrolyze polysaccharides. Insoluble and solid supports are noteworthy in immobilization of enzymes for industry because of increasing enzyme stability. In this study, immobilization of alpha amylase in electrospun polyethersulfone (PES) nanofibers was studied. Covalent immobilization of the enzyme was done through the carboxyl groups made by oxygen plasma treatment and 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as a carboxyl group activator agent. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) and contact angle analysis proved enzyme immobilization. The optimum conditions determined and the catalytic parameters of immobilized enzyme were calculated. The results of this investigation showed that the optimum pH of immobilized enzyme was displaced toward acidic region by 1 unit. Comparison of the optimum temperature for immobilized and free amylase revealed 10°C increasing for the immobilized enzyme. Furthermore, the kinetic parameters, Vmax and Km for the immobilized enzyme were the same and higher than those of free ones, respectively. Storage stability of the immobilized amylase was obviously improved. The results illustrated that nanofibrous supported alpha amylase is a new and suitable matrix for industrial applications.