Microbial Surfactants: A Review

Abstract

Biosurfactants are amphiphilic compounds produced on living surfaces, mostly microbial cell surface or excreted extracellularly and contain hydrophobic and hydrophilic moieties, that reduce surface tension and interfacial tension between individual molecules at the surface and interface respectively. Several biosurfactants have high surface activity and low critical micelle concentration (CMC) and are therefore, promising substitutes for synthetic surfactants. The oils and fats derived from plants are used for the manufacture of biosurfactants. A large amount of wastes are generated by oils and fats industries, residual oils, tallow, marine oils, soapstock, frying oils, cassava flour mill effluent. The use of above industrial fatty waste has great potential for growth and transformation. The agro industrial by product acid, whey, olive oil mill effluent, molasses can also be used for biosurfactant production. Biosurfactants have several advantages over the chemical surfactants such as lower toxicity, higher biodegradability, better environmental compatibility, higher foaming, higher selectivity and specific gravity at extreme temperature, pH and salinity and the ability to be synthesized from renewable feedstock. That's why the demand of biosurfactants are increasing day by day. © 2006, Japan Oil Chemists' Society. All rights reserved.