Protein purification by ultrafiltration with pre-treated membrane

The paper discusses separation of lysozyme from chicken egg white (CEW) by ultrafiltration using 50 kDa MWCO polysulfone membrane pre-treated with myoglobin. The transmission of lysozyme was about 26% higher with the pre-treated membrane than with the native membrane. The transmission of the other major CEW proteins, i.e., ovalbumin and conalbumin, were found to depend on the transmembrane pressure (TMP); transmission decreased with increase in TMP. Thus, using a combination of surface pre-treatment and TMP adjustment, conditions were obtained whereby lysozyme was totally transmitted while ovalbumin and other CEW proteins were almost totally rejected. At a TMP of 20 kPa, the percentage purity of lysozyme was about 18%, while at a TMP of 120 kPa, the purity was greater than 96%.