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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