Biosurfactants : An overview

A large number of biosurfactants are synthesized by bacteria, yeasts and algae. Biosurfactants display a range of structures but have the common ability to cause emulsification of oil-water mixtures. Biosurfactants are grouped as glycolipids, lipopeptides, phospholipids, fatty acids/neutral lipids, flavolipids, polymeric and particulate compounds. Low molecular weight biosurfactants (glycolipids, lipopeptides) lower surface and interfacial tensions. High molecular weight biosurfactants (polymeric and paniculate compounds) bind tightly to surfaces. Biosurfactants have many important advantages over chemical surfactants. These include mild production conditions, lower toxicity. higher biodegradability and environmental compatibility. Their production, biosynthesis and genetic aspects have been discussed. A large number of industrial uses for biosurfactants include: the remediation of organic- and metal-contaminated sites, the enhanced transport of bacteria, enhanced oil recovery, as cosmetic additives, in biological control, in food, environmental, specialty chemicals, agriculture. and pharmaceutical industries.