ABSTRACT
Biosurfactants are of biological or microbial origins which are being preferred in place of chemical surfactants in recent years as antimicrobial and biodegradable agents. Biosurfactants are produced by several microorganisms which include different species of Acinetobacter and Bacillus, Candida Antarctica, Pseudomonas aeruginosa, yeasts and molds. Biosurfactants are a structurally diverse group of amphiphilic biomolecules with both hydrophilic and hydrophobic moieties. They are categorised into two groups on the basis of their molecular weight i.e biosurfactants with low and high molecular weight. The first category includes glycolipids and lipopeptides, however, the second category includes polymeric biosurfactants. Due to their biodegradability and low toxicity nature, biosurfactants are used in remediation technologies as an alternative to the synthetic surfactants. Some reports are also available about production of biosurfactants by bacterial consortium isolated from hydrocarbon contaminated soils or marine water columns. It has been reported that the amount of surfactant production was more in a single bacterial species when compared to the production by mixed bacterial consortium which indicates that there may be a competition between the bacteria for nutrient substrate. There is a need for eco-friendly and biodegradable surfactants (ionic or non-ionic) for reliable environmental clean-up. Commercially, viable biosurfactants have to be economically more competitive than chemical surfactants. They have several applications in agriculture, industry, medicine and petroleum sectors. Under stressed environment, physiologically active microbes produce biosurfactants which have more antimicrobial activity and the ability to make substrates readily available for uptake by the cells. The potential role of biosurfactants in food industry, agro-food biotechnology and agriculture, as antimicrobials and in pharmaceutical, oil industry as bioremedials of pollutants will be also be discussed in this article.
