固定化细胞合成生物表面活性剂鼠李糖脂的研究

从石油受污环境中分离筛选得到一株高产鼠李糖脂(rhamnolipid,RL)的假单胞菌(Pseudomonas sp.)B3。在游离细胞合成鼠李糖脂的基础上,应用包埋与交联相结合的复合固定化方法制备出性能优良的固定化细胞。以二次回归方程预测模型为基础,对发酵条件进行优化,得到B3固定化细胞合成RL的最优条件为:接种量15%,初始pH 7.0,合成温度38℃,120r·min-1振荡培养100h,RL的产量达到4 843.25mg·L-1,比游离细胞提高56.42%。制备的固定化细胞连续使用3个发酵周期,RL的产量均保持在4 517.75mg·L-1以上,说明B3固定化细胞具有用于连续发酵合成RL的可行性。

Synthesis of Biosurfactant Rhamnolipid by Immobilized Cells

Pseudomonas sp.B3 with high-yielding rhamnolipid(RL)was isolated from petroleum contaminated environment.Based on the synthesis of RL from free cells,immobilized cells with high performance were prepared using embedding-crosslinking complex immobilization method.The quadratic regression equation prediction model was applied to optimize the fermentation process.The optimized conditions were as follows:inoculums 15%,initial pH7.0,fermentation temperature 38℃,120r·min-1 shaking and culture time 100 h.The yield of RL was up to 4 843.25mg·L-1 and 56.42%higher than that from free cells.The B3 immobilized cells showed good stability of biosynthesis,after three cycles of fermentation,the RL yield could be still kept above 4 517.75mg·L-1.