BIOSURFACTANTS AND
BIOEMULSIFIERS
Amritha M. S.2010-09-115
SurfactantsSubstance which reduces surface/interfacial tension between two phases
Water & Oil are mortal
enemies
Surfactants acts as clamp
binding Water & Oil are together
Surface Tension –
Force between
two liquids
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Biosurfactants
Naturally occuring surface-active
compounds derived from microbial source
Extracellulary by bacteria and fungi
Source
Soil microbes
• Pseudomonas, • Bacillus,• Sphingomonas , • Actinobacteria .
Marine microbes
• Pseudoalteromonas,• Halomonas,• Alcanivorax ,• Acinetobacter.
Advantages over chemical surfactants
High efficiency in broad range of pH and salt concentrations,
Thermo stability, low toxicity, Good biodegradability, Ecological acceptability.
APPLICATIONS
1. Microbial enhanced oil recovery (MEOR)• by lowering interfacial tension at the oil–rock
interface.• To produce bio surfactant in
situ, microorganisms in the reservoir are usually provided with low-cost substrates, such as molasses and inorganic nutrients, to promote growth and surfactant production
2. Hydrocarbon degradation• Hydrocarbon-utilizing microorganisms
excrete a variety of biosurfactants.3. Pesticide-specific biosurfactants• Due to biodegradative property of
biosurfactant
Pesticide degradation and formulation
• Degradation of pesticides• Replacement of synthetic surfactants with the
biosurfactants in the pesticide formulation and clean-up
• Hexa-chlorocyclohexane (HCH) is still the highest ranking pesticide used in India (carcinogen).
• Pseudomonas Ptm produced extracellular biosurfactant in a mineral medium containing HCH
BIOEMULSIFIERS
High molecular weight biopolymers of polysaccharides, lipopolysaccharides proteins or lipo proteins are collectivelly termed as bioemulsifiers or bioemulsans
Another group of ‘biosurfactants’• Microbial products, which form and
stabilize water in oil or oil in water emulsions
Source
Bacteria• Acinetobacter
radioresistens- alasan• Azotobacter vinelandii• Microbacterium sp.
fungi• Candida lipolytica
- liposan• Candida utilis• Trichosporon
mycotoxinivorans
How they differ?
Biosurfactants• Low molecular weight
compounds• Composed of generally
glycolipids or lipopeptides in which rhamnolipids, trehalolipid and sophalo lipid compounds are dominant
• Have both Surface tension reduction and emulsification activity
• It is used for the stabilization of emulsion
Bioemulsifiers• High molecular weight
compounds• Composed of
Polysaccharides, lipopolysaccharides , proteins or lipo proteins or mixture of these
• Only emulsification• The emulsion formed
where not stable
Application in bioremediation
• Azotobacter vinelandii – soil oil spill remediation
• Candida utilis - food industry for the removal of waste canola oil from industry effluent
• Trichosporon mycotoxinivorans -Bio emulsifier producing yeast strain isolated from effluents of the dairy industry, with ability to emulsify different hydrophobic substrates.
• Microbacterium sp. strains isolated from mangrove and their application to remove cadmiun and zinc from hazardous industrial residue
Herbicides and pesticides
• Agriculture, in various formulations of herbicides and pesticides.
• The active compounds in these formulations are hydrophobic, so emulsifiers are required for dispersing them in the aqueous solutions.
• Eg: Bioemulsifier- glycolipopeptides produced by strains of bacillus for emulsifying immiscible organophosphorus pesticides.
Diary, textile and paper industry
• In diary products the addition of polymeric emulsifiers improves the texture and creaminess.
• Adhere to the oil, it is concentrated in the oil/water interface, and stay when water is removed.
• These properties are important for applications in textile or paper industries.
• Saccharomyces cerevisiae - bioemulsifier is mannoprotein for mayonnaise production with several different formulations
Medical field
• Some bioemulsifiers have antibacterial, antifungal and antiviral activities which make them promising candidate for treatment of disease.
• Problems……a. Less yieldb. Difficulty in extraction- crude form
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