One-step lactoferrin purification from bovine whey and colostrum by affinity membrane chromatography

Hollow fibres with high lactoferrin (Lf) adsorption capacity were synthesised by grafting a glycidyl methacrylate/dimethyl acrylamide copolymer to polysulfone membranes and attaching the Red HE-3B dye to them. A maximum capacity of 111.0 mg Lf ml−1 membrane, far higher than that obtained with the same ligand immobilised on agarose beads (9.3 mg ml−1), was found from isotherms developed with Lf aqueous solutions. With colostrum as the Lf source in a batch system, 91% of the Lf contained in that raw material was adsorbed by the dye-membranes while only 56% was adsorbed by the dye-agarose beads. The best desorption performance was achieved with 2 M NaCl in 25% ethylene glycol: 99% and 80% from the hollow fibres and agarose beads, respectively. A cartridge assembled with dye hollow fibres showed a productivity of 501.5 μg h−1 ml−1 Lf, 500% higher than that attained with the dye-agarose matrix. A 94% purity was achieved in only one step, casein and immunoglobulin being the only contaminants. As Lf is usually utilised as a food supplement, Lf obtained by the method described comply with the needs of a final product.