新型生物食品防腐剂ε-聚赖氨酸的提取

Purification of a novel microbial food preservative ε-polylysine from fermentation broth

为建立从发酵液中高效分离提取ε-聚赖氨酸（ε-PL）的方法,比较了离子交换和膜分离以及二者组合对ε-PL分离提取的影响。实验结果显示,在离子交换之前增加一个30 k超滤操作能够很好地去除杂蛋白,并提高离子交换树脂对ε-PL吸附容量;最终样品纯度达到95.3%,收率65.4%;获得的样品聚合度分布范围为9~29,平均分子质量为2 602.3Da;且样品对细菌具有强烈的抑制作用。这表明,离子交换和膜分离组合策略是从发酵液中高效分离与提取ε-PL的核心单元操作工序。

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 ul- trafiltration 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 experi- ments 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.