Biosurfactants Production and Applications PDF

# Biosurfactants Production and Applications ## The surfactant - Organic compound - Amphiphilic - Lowers the surface tension - Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents ## The Biosurfactant - Surface-active biomolecules - Extracellular excretion by microbes - A...

# Biosurfactants Production and Applications ## The surfactant - Organic compound - Amphiphilic - Lowers the surface tension - Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents ## The Biosurfactant - Surface-active biomolecules - Extracellular excretion by microbes - Amphiphilic compounds - hydrophilic and hydrophobic regions ## Structure Surface + Active + Agent The image shows a hydrophilic (water-loving) head of a surfactant, and a hydrophobic (water-hating) tail, which come together in water to form a surfactant-stabilized oil droplet. ## Properties - Surface and interfacial activity - Tolerance to temperature, pH and ions - Biodegradability - Low toxicity - Biocompatibility and digestibility ## Classification Note: Based on chemical structure and their microbial origin. - Glycolipids - Phospholipids - Polymeric biosurfactants - Lipopeptides (surfactin) - The best known glycolipids are rhamnolipids, sophorolipids and trehalolipids ## Biosurfactant producers - Acinetobacter sp - Bacillus sp - Candida antartica - Pseudomonas aeruginosa ## Applications of Biosurfactants ### Biosurfactant in MEOR (in the Oil Industry) - Recently used - Bacillus subtilis - Bacillus licheniformis JF-2 - Pseudomonas aeruginosa - Torulopsis bombicola These have been reported to utilize crude oil & hydrocarbons as sole carbon sources & can be used for oil spill clean-ups ### Biosurfactants in Degradation Processes - Pseudomonas species in degrading aliphatic and aromatic hydrocarbons, crude oil under laboratory conditions only. - Degradation from 85% to 97% ### Application of Biosurfactants in Agriculture - Fengycins are also reported to possess antifungal activity and therefore may be employed in biocontrol of plant diseases ## USE OF FUNGI IN BIOREMEDIATION - Candida can degrade formaldehyde. - Gibeberella can degrade cyanide. - Slurry-phase bioremediation is useful too but only for small amounts of contaminated soil. - Composting can be used to degrade household wastes. ### WHITE ROT FUNGI - White rot fungi can degrade organic pollutants in soil and effluent and decolorize kraft black liquor, e.g *Phanerochaete chrysosporium* can produce aromatic mixtures with its lignolytic system. - Pentachlorophenol, dichlorodiphenyltrichloroethane (e.g. DDT), even TNT (trinitrotoluene) can be degraded by white rot fungi. ## Degradation of Organopollutants - *Phanerochaete chrysosporium*, white rot fungi, acts to break down pollutants by adding an -OH group. - Hydroxilating makes the compound more polar. ## ADVANTAGES AND DISADVANTAGES ### ADVANTAGES OF BIOREMEDIATION - Bioremediation is a natural process and is therefore perceived by the public. - Bioremediation is useful for the complete destruction of a wide variety of contaminants. - Instead of transferring contaminants from one environmental medium to another, for example, from land to water or air, the complete destruction of target pollutants is possible. - Bioremediation can often be carried out on site, often without causing a major disruption of normal activities. - Bioremediation can prove less expensive than other technologies that are used for cleanup of hazardous waste. ### DISADVANTAGES OF BIOREMEDIATION - Bioremediation is limited to those compounds that are biodegradable. Not all compounds are susceptible to rapid and complete degradation. - There are some concerns that the products of biodegradation may be more persistent or toxic than the parent compound. - Biological processes are often highly specific. microbial populations, suitable environmental growth conditions, and appropriate levels of nutrients and contaminants. - It is difficult to extrapolate (deduce) from bench and pilot-scale studies to fullscale field operations. - Bioremediation often takes longer than other treatment options.