STARCH-STARKE, cilt.73, sa.7-8, 2021 (SCI-Expanded)
The aims of this study are to synthesize and characterize poly (2-hydroxyethyl methacrylate-co-poly (ethylene glycol) methacrylate) (P(HEMA-co-PEG500MA)) structures containing polyethylene glycol (PEG) side groups and to investigate their possible use in alpha-amylase immobilization. For this purpose, P(HEMA-co-PEG500MA) copolymer structures are synthesized by using different monomer ratios. P(HEMA-co-PEG500MA) copolymer structures are confirmed by Fourier transform infrared spectroscopy (FTIR), and elemental analysis techniques. In addition, thermal, and morphological properties of the copolymers are investigated by thermal gravimetric analysis/differential scanning calorimetry, and scanning electron microscopy (SEM). Afterward, alpha-amylase from Aspergillus oryzae is immobilized on synthesized copolymer support by using physical interactions. The success of immobilization is elucidated via FTIR, SEM, and energy dispersive X-ray spectroscopy (EDX) methods. In addition, the influences of temperature, pH, storage time, and repeated uses on the activity of free and immobilized alpha-amylase are investigated. According to the outcomes, the immobilized alpha-amylase possesses a better pH and thermal resistance than the free one. Additionally, the immobilized alpha-amylase maintains about 53% of its original activity after eight reuses and it exhibits about 50% relative activity after 28 days of storage. In conclusion, the immobilized alpha-amylase can be utilized as a potential efficient catalyst to produce maltose from the hydrolysis of starch.