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.