Pseudomonas sp.LKY-5产生的表面活性剂提取及其稳定性研究

STUDY ON BIOSURFACTANT PRODUCED BY PSEUDOMONASSP.LKY-5 AND ITS STABILITY

针对二苯并噻吩高效降解菌Pseudomonas sp.LKY-5降解过程中产生表面活性剂的现象,进行碳源优化,将提取分离出的表面活性剂进行化学组分分析和理化性质测定,考察温度、pH、无机离子对其表面活性稳定性的影响。结果表明,花生油为Pseudomonas sp.LKY-5产生表面活性剂的最佳碳源,产生的表面活性剂为鼠李糖脂,产量为0.15g/L,临界胶束浓度（CMC）为180mg/L,亲水亲油平衡值（HLB）为12.3,对柴油24h的乳化能力达61%。该表面活性剂在温度30-80℃、pH 6-13的条件下表面活性稳定,能够耐受200g/L的NaCl或MgCl2以及20g/L的CaCl2,稳定性能良好。

The Pseudomonas sp.LKY-5produces biosurfactant during biodegradation process of dibenzothiophene.This work optimizes the carbon sources for biosurfactant production,verifies the biosurfactant by thin-layer chromatography,and then determines its physicochemical properties,and investigates the influence of temperature,pH and inorganic ions on the active stability of biosurfactant.The results show that the biosurfactant produced is rhamnolipid,and peanut oil is the optimal carbon source for the production of biosurfactant with a yield of 0.15g/L.The critical micelle concentration（CMC）and hydrophile-lipophile balance（HLB）value of biosurfactant are 180 mg/L and 12.3,respectively.Twenty-four hours diesel emulsification ability is 61%.The biosurfactant is stable at conditions of a temperature of 30—80℃,apH of 6—13,and can tolerate the environment of 200g/L NaCl（or MgCl2）or 20g/L CaCl2.