ABSTRACT
Biosurfactants are low molecular weight amphiphilic (both hydrophilic and hydrophobic) biological surface active compounds. They are secondary metabolites produced extracellularly by microorganisms as part of the cell membrane from various substances including sugars, oils and wastes. They are biodegradable non-toxic and eco-friendly materials. The properties of microbial biosurfactants are identified with their surface movement, resilience to pH, temperature and ionic quality, biodegradability, low poisonous quality, emulsifying and demulsifying capacity. Biosurfactants derived from the microbial sources (bacteria, yeast and filamentous mold fungi) are classified according to their chemical composition and the microbial sources. Different organic compounds are used by microorganisms to be utilized asthe source of carbon for their growth. Some of the common types of Biosurfactants are Glycolipids (Rhamnolipids, Trehalose lipids, Sophorolipids and Mannosylerythyerythritol lipids), Lipopeptides (Surfactin or Iturin or Fengycin, Viscosin, Lichenysin and Serrawettin), Phospholipids, Surface active antibiotics (Gramicidin, Polymyxin and Antibiotic TA), Fatty acids or Neutral lipids (Corinomicolic acid), Polymeric surfactants (Emulsan, Alasan, Liposan and Lipomanan) and Particulate biosurfactants (Vesicles and Whole microbial cells). Many biosurfactant properties such as emulsification and de-emulsification, foaming, water binding capacity, spreading and wetting properties effect on viscosity and on product consistency can efficiently be utilized by the industries. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries.
