Abstract

Surfactants are widely used for various purposes in industry, but for many years were mainly chemically synthesized. It has only been in the past few decades that biological surface-active compounds (biosurfactants) have been described. Biosurfactants are gaining prominence and have already taken over for a number of important industrial uses, due to their advantages of biodegradability, production on renewable resources and functionality under extreme conditions; particularly those pertaining during tertiary crude-oil recovery. Conflicting reports exist concerning their efficacy and the economics of both their production and application. At present, their uses are mainly in the oil and petroleum industries, where they are employed primarily for their emulsification capacity in both tertiary recovery and polluted-sites remediation. However, caution is frequently exercised with respect to their use because of possible subsequent microbial contamination of either underground oil reservoirs or products. The limited successes and applications for biosurfactants' production, recovery, use in oil pollution control, oil storage tank clean-up and enhanced oil-recovery are reviewed from the technological point of view.