Egg White Lysozyme Purification by Ultrafiltration and Affinity Chromatography

ABSTRACT Isolation and purification of lysozyme from hen egg white was studied using a two‐step procedure. The egg white was diluted 5‐ to 9‐fold with sodium phosphate buffer, and then processed by sequential dilution diafiltration using a UF membrane (molecular weight cut‐off 300,000 dalton). The membrane process increased the specific activity of lysozyme 6‐fold, and recovered 96% of lysozyme activity. The permeate from diafiltration was further purified by affinity chromatography using chitin as adsorbent. The second step of the process yielded a product of specific activity of 70,400 units/mg protein. The overall lysozyme recovery was 79%.