To develop an efficiency strategy for the purification of ε-polylysine( ε-PL) from fermentation broth,ion-exchange adsorption or /and membrane separation techniques had been employed and compared in this study. The results indicated that the removal of other proteins and the capacity of resin to ε-PL were enhanced significantly if ultrafiltration with 30 kDa MWCO was supplemented before ion-exchange adsorption. Finally,ε-PL sample achieved the purity of 95. 3% with the overall yield of 65. 4%. MALDI-TOF MS showed that the degree of polymerization of the ε-PL sample was mainly distributed in the range of 9 ~ 29 and the average molecular weight was 2602. 3. The experiments of minimal inhibitory showed that the ε-PL sample had a superior antibacterial effect on bacteria. Therefore,it was necessary to combine ion-exchange adsorption with membrane separation technique for the extraction of ε-PL from fermentation broth.
