Cibacron Blue F3GA attached mP(HEMA) beads for casein purification

Magnetic poly(2-hydroxyethylmethacrylate) [m P(HEMA)] beads carrying Cibacron Blue F3GA were prepared by suspension polymerization of HEMA. Cibacron Blue F3GA was covalently coupled with magnetic poly(HEMA) microbeads via the nucleophilic substitution reaction between the chloride of its triazine ring and the hydroxyl groups of the HEMA molecules under alkaline conditions. Dye-attached mP(HEMA) beads were characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy, elemental analysis, swelling studies. The affinity sorbent carrying 68.3micromol Cibacron Blue F3GA/g was in the 100-140 micrometer particle size range. The swelling ratio of the mP(HEMA) was % 62.12. Adsorption studies were performed under different conditions in batch system (i.e., pH, protein initial concentration, temperature, and ionic strength) and than in magnetically stabilized fluidized bed (MSFB) system. The maximum adsorption was observed at pH 5.0, which is the isoelectric pH of beta casein. The maximum amount of beta-casein adsorption from aqueous solution was 57.52 mg/g in batch system and 72.09 mg/g in MSFB system at pH 5.0 (Studied casein concentration: 0.5 mg/ml). Up to 90 percent of the adsorbed beta-casein was removed by 1.5 M NaCl as elution agent. We concluded that Cibacron Blue F3GA attached magnetic poly(HEMA) could be repeatedly applied for beta-casein adsorption without significant losses in the adsorption capacity.