采用双水相萃取技术提取ε-聚赖氨酸

Aqueous two-phase extraction and purification of ε-poly-L-lysine from fermentation broth

对以双水相萃取新技术提取ε-聚赖氨酸(ε-poly-L-lysine,ε-PL)作了较深入的探索研究。通过对多个双水相体系的筛选,确定了利用乙醇/硫酸铵双水相体系来萃取ε-PL的方案,得到的最佳萃取条件为:pH 9.5,乙醇/硫酸铵质量分数组成为20%/20%,分配系数和收率分别可以达到18.33和98.02%。进一步探究了多级萃取方式对ε-PL萃取效果的影响,发现3次萃取的效果最好,蛋白质和色素去除率分别达到85.66%和60.00%,ε-PL收率为96.15%。最后,收集经过3次萃取后的上相,利用超滤膜进行简单脱盐浓缩,产品的收率和纯度分别可以达到68.28%和92.39%。

An integrated fermentation-separation process for the production ofε-poly-L-lysine(ε-PL)was investigated.Through the screening of several aqueous two-phase systems,the extraction ofε-PL by ethanol/ammonium sulfate aqueous two-phase system was investigated in detail.The results indicated that the highest partition coefficient(18.33)and recovery(98.02%)ofε-PL were obtained with an aqueous two-phase system composed of 20%(w/w)ethanol and 20%(w/w)ammonium sulfate,pH9.5.The effect of multi-stage extraction was investigated.It was found that the effect of extraction for three times was the best,the removal rate of protein and pigment were 85.66%and 60.00%,respectively,and the yield ofε-PL was 96.15%.Finally,the top phase after three times of extraction was desalted and concentrated by ultrafiltration membrane,and the yield and purity of the product reached 68.28%and 92.39%,respectively.