Adsorption of lysozyme from aqueous solutions by a novel bentonite-tyrptophane (Bent-Trp) microcomposite affinity sorbent

This study deals with developing bentonite-tryptophan (Bent-Trp) microcomposite affinity sorbent (38-105 μm) for lysozyme adsorption from aqueous solutions. The structural analysis results of Bent-Trp microcomposites obtained from X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), thermal (TG-DTG/DTA) and elemental analysis techniques clearly pointed out that the pseudo-biospecific affinity ligand L-Tryptophan was penetrated into interlayer space of the bentonite by diplacing water molecules and an elemental analysis of immobilized L-Tryptophan for nitrogen was 541.3 μmol g−1 bentonite. The effects of initial concentration, pH, and temperature on the adsorption efficiency of this sorbent were also studied in a batch system. The maximum amount of lysozyme adsorption from aqueous solution was determined as 365.16 mg/g at pH 10.0 and 1.25 mg/mL initial concentration of lysozyme, while the non-specific adsorption of lysozyme was very low (4.21 mg g−1 sorbent). We concluded that Bent-Trp microcomposite affinity sorbents could be repeatedly applied for lysozyme adsorption without significant losses in the adsorption capacity.