Direct lysozyme separation from egg white by dye membrane affinity chromatography

An affinity membrane from hydrophylised polyethylene hollow fibre as the su pport matrix was prepared. Red HE-3B was immobilised on the membrane and th e adsorption behaviour of pure lysozyme solutions and homogenised egg white was investigated. Dye density (1.7 mu mol ml(-1)) and maximum binding capa city (26 mg lysozymeml(-1)) are comparable to those of commercial gel matri ces. Dynamic binding capacity did not change when residence time was reduce d from 3 to 1 min. A method for direct lysozyme separation from egg white w as developed, with a productivity of 12 kp lysozyme m(-3) h(-1). The purity of the eluted lysozyme, as determined by HPLC, was 88%, with a recovery of 92%. Dynamic capacity was kept constant at 70% of the maximum binding capa city for at least 10 cycles through membrane regeneration with 0.1 M NaOH a nd 1 M NaCl. Functional properties of egg white, as judged by viscosity and foaming capacity measurements, did not change after the chromatographic ly sozyme depletion. (C) 1999 Society of Chemical Industry.