【摘要】 研究了微量非离子表面活性剂Tween-80和Span-20对发酵液中乳链菌肽(Nisin)泡沫分离的影响.结果表明,发酵液泡沫分离时泡沫层轴向气泡直径、连续通气过程的泡沫层高度、泡沫层平均持气量等均因添加活性剂而明显变化.不同体系气泡大小为,含0.2g/LSpan-20发酵液>含0.5g/LSpan-20发酵液>发酵液>含0.2g/LTween-80发酵液>含0.5g/LTween-80发酵液;Tween-80的加入破坏了气泡表面的网状结构,因而泡沫层持气量较高;连续通气时,2种表面活性剂都会引起泡沫层高度降低,但Tween-80会增加泡沫层的稳定性.当Tween-80浓度达0.5g/L时,Nisin的收率大幅度提高,原因是分离过程中Nisin失活率减少.更多还原

【Abstract】 The effects of Tween-80 and Span-20 on foam fractionation of Nisin(a food additive) fermentation broth were studied by using a single foam column.The results indicated that bubble size distribution,foam height and average gas holdup of the foam layer of the mixed system containing Tween-80 and Span-20 changed obviously from Nisin fermentation broth.The bubble size order of different mixed systems was:fermentation broth containing 0.2 g/L Span-20>fermentation broth containing 0.5 g/L Span-20>fermentation broth>fermentation broth containing 0.2 g/L Tween-80>fermentation broth containing 0.5 g/L Tween-80.The addition of surfactants decreased the height of foam layer and gas holdup,but Tween-80 increased the foam stability.And Tween-80 reduced the denaturation rate of Nisin in foam fractionation,so the separation effect was improved distinctly.更多还原