IMAC application of extracellular polymeric substances doped composite membranes for ?-amylase immobilization and kinetic studies

Immobilized metal affinity chromatography (IMAC), extensively utilized technique in affinity chromatography, has proven to be highly effective in purifying ?-amylase, a crucial enzyme in industrial applications. Here, Poly (2-hydroxyethyl methacrylate) (PHEMA) based composite membranes were fabricated using the radical copolymerization technique in a petri dish. Extracellular polymeric materials (EPS) as the metal binding agent. The attachment of Cu2+ ions to the membranes occurred through the utilization of EPSs (Cu2+-EPS). The membranes having Cu2+-EPS (Cu2+-EPS-PM) were subjected to various characterization techniques, including scanning electron microscopy (SEM), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), swelling tests, and surface area measurements. The investigation also encompassed the examination of various factors, including pH, initial ?-amylase concentration, temperature, and ionic strength, that exert an influence on the adsorption of ?-amylase from an aqueous medium. The Cu2+-EPS-PMs demonstrated maximum adsorption capacity with a value of 54.2 mg/g polymer (pH 5.0 sodium acetate buffer, temperature: 25°C, initial ?-amylase concentration of 2 mg/mL). Additionally, it has been observed that the enzyme is able to be used in adsorption and desorption cycles on Cu2+-EPS-PM many times. The investigation also focused on examining the impact of pH, temperature, storage, and operational stability over the activities of both free and immobilized ?-amylase. The outcomes showed that immobilization had positive effects on activity.