鼠李糖脂与疏水底物及其降解菌的相互作用

通过鼠李糖脂对假单胞菌GP3A菌株降解芘的增溶和降解实验，研究了在鼠李糖脂作用下，菌体细胞表面疏水性和脂多糖含量的变化、菌体表面基团与生物表面活性剂分子的键合作用以及相应疏水底物的增溶和降解．结果表明，当鼠李糖脂浓度高于其临界胶束浓度（60mg·L^-1）时，能显著增加疏水底物芘的表观溶解度；生物表面活性剂能通过溶出细...

Interrelationships of Rhamnolipids, Hydrophobic Substrate and Degrading Bacteria

The effect of rhamnolipids on pyrene degradation by Pseudomonas sp. GP3A was investigated to explore the interrelationships of biosurfactant, hydrophobic substrate and degrading bacteria. The cell surface hydrophobicity, lipopolysaccharide, hydrogen bond, bacterial biomass and pyrene degradation were determined. The results showed that the apparent solubility of pyrene was enhanced significantly when the concentration of rhamnolipids was higher than critical micelle concentration (CMC) of 60 mg x L(-1). Biosurfactant can increase the cell surface hydrophobicity by releasing the component of the cell wall-lipopolysaccharide; With the increase of cell surface hydrophobicity from 12% to 55%, bacterial biomass increased from 4.4 x 10(6) CFU x mL(-1) to 1.2 x 10(7) CFU x mL(-1), corresponding with the increase of pyrene degradation from 16% to 44%. Meanwhile, hydrogen bond was formed between biosurfactant and bacteria, which was beneficial to hydrophobic substrate degradation. The half-life of pyrene was shorten significantly. The average residual rate of pyrene in 10 days was 81% without rhamnolipids, but decreased to 57%, 41%, 33% and 26%, respectively with the addition of 20, 50, 200 and 500 mg x L(-1) of rhamnolipids.