Microbial Biosurfactants Remediation of Contaminated Soils

Microbial biosurfactants are amphiphilic molecules comprising of lipids, peptides, sachharides, or their combinations of moieties. The surface active properties of the biosurfactants endorse their applications in the field of bioremediation, biodegradation, enhanced oil recovery, food processing, pharmaceutics, and many more. In this chapter, the production of biosurfactants from isolated strains, their interfacial properties, and stability for remediation of oil contaminated soil are discussed. The isolation, screening, and identification of biosurfactant-producing microbes are the prerequisites. Hydrocarbon contaminated soil is the most promising site for isolating the biosurfactant producing bacteria. Biosurfactants exhibit very low CMC values as compared to the chemical surfactants, and are found to be stable under extreme environmental conditions, i.e., temperature in the range of 30°C to 100°C, pH in the range of 3 to 12, and salinity up to 10 percent. Biosurfactants emulsify the hydrocarbons by enhancing their water solubility, reducing surface tension, and increasing the displacement of oil substances from oil contaminated soil particles.