This paper discusses the purification of lysozyme from chicken egg white us
ing hollow-fibre ultrafiltration (30 kDa MWCO, polysulphone membrane). Lyso
zyme is preferentially transmitted through the membrane while the membrane
largely retains other egg white proteins. Improvement in system hydrodynami
cs resulted in an increase in permeate flux while lysozyme transmission rem
ained unaffected, leading to higher productivity. The percentage purity of
lysozyme obtained was generally insensitive to system hydrodynamics. The pe
rmeate flux and productivity increased with increase in transmembrane press
ure (TMP) before levelling off around 0.7 bar. However, the TMP did not hav
e any pronounced effect on the transmission and the purity of lysozyme. Exp
eriments carried out in the diafiltration mode showed that moderately pure
lysozyme (80-90%) could be obtained in an extended operation. (C) 2000 Publ
ished by Elsevier Science S.A.