鼠李糖脂对铜绿假单胞菌降解颗粒有机质的影响

通过好氧降解实验研究了生物表面活性剂鼠李糖脂对1株铜绿假单胞菌(Pseudomonas Aeruginosa)降解颗粒有机质的影响,着重探讨了其作用方式,并与TritonX-100和SDS等2种化学表面活性剂作了对比.结果表明,浓度高于临界胶束浓度的鼠李糖脂在基质表面的等温吸附呈线性规律.鼠李糖脂在基质和微生物表面的吸附使菌体在基质表面的吸附性能减弱.鼠李糖脂和2种化学表面活性剂的物化作用使基质水分得以较长时间地保持,并加强了有机质在基质液相中的分散.在鼠李糖脂的作用下,有机质的降解从颗粒表面转移到液相,降解方式发生了改变.通过以上作用,鼠李糖脂促进了微生物的生长和有机质的降解.SDS和TritonX-100对有机质颗粒的降解也产生了一定的促进作用.

Effects of rhamnolipid on degradation of granule organics by a Pseudomonas Aeruginosa strain

The effect of rhamnolipid biosurfactant on degradation of granule organics by a Pseudomonas aeruginosa was studied through an aerobic degradation experiment, and the mechanism for its function was basically revealed and compared with two synthetic surfactants, SDS and Triton X-100. Isothermal adsorption of rhamnolipid on the substrate was linear to the rhamnolipid concentration when its concentration was higher than CMC. Adhesion of bacteria on the substrate surface was weakened as the result of rhamnolipid adsorption. Rhamnolipid effectively impeded water evaporation in the medium and enhanced dispersion of organic matters into the medium aqueous phase. In the presence of rhamnolipid, the degradation site changed from the granule surface to the medium aqueous phase and it led to a different degradation manner. The growth of the bacterium and the degradation of the organic matter were strengthened in the presence of rhamnolipid. Triton X-100 and SDS also have some of the above functions, but not as significant.