A short presentation on biosurfactants

1. VIDYA.V
DEPARTMENT OF
BIOTECHNOLOGY
STELLA MARIS COLLEGE
(AUTONOMOUS )

2.  Pollution caused by petroleum hydrocarbons in environment leads to
significant ecological and social problems .
 Clean up of oil spill is a tedious process.
 Biodegradation in aquatic environment is limited by the availability of
nutrients (nitrogen and phosphorus) which are necessary for microbial
growth.
 Biosurfactant the solution to oil spills.
 They have not been employed in industry due to the relatively high
production costs
 Alternative cheaper substrates have been used for production

3. International Journal of Molecular Sciences
ISSN 1422-0067

4.  Biosurfactants, organic compounds produced in nature for the
exact purpose of oil dispersion and remediation.
Produced by microbes such as yeast, bacteria and fungi.
 Biosurfactants are amphiphilic compounds—meaning they
attract both lipids (such as oil) and water — and serve to reduce
the surface tension between the two substances.
Source: American
journal of
Microbiology

5. Petroleum bioremediation is carried out by microorganisms
capable of utilizing hydrocarbons as a source of energy and
Carbon.
These microorganisms are ubiquitous in
nature and are capable of degrading the various types of
hydrocarbons — short-chain, long-chain and numerous
aromatic compounds, including polycyclic aromatic hydrocarbons.
All these compounds have low solubility in
water.
This fact, coupled to the fact that the first step in
hydrocarbon degradation involves a membrane-bound
oxygenase, makes it essential for bacteria to come in direct
contact with the hydrocarbon substrates.
One biological strategy that can enhance contact between bacteria
and water-insoluble hydrocarbons is emulsification of the
hydrocarbon.
Therefore, bacteria growing on petroleum usually produce potent
emulsifiers.
These surfactants help to disperse the oil, increase the
surface area for growth, and help detach the bacteria from
the oil droplets after the utilizable hydrocarbon has been
depleted

6.  Biosurfactants are mainly produced by aerobic
microorganisms in aqueous media with a carbon source
feedstock, such as carbohydrates, hydrocarbons, fats, and oils
 Biosurfactants are surface active organic compounds produced
by bacteria.
 Applications of biosurfactant includes excellent detergency,
emulsification, microbial enhancement, resource recovering
(oil) which make surfactants substitute with some of the most
versatile process chemicals.
 Biosurfactants have the ability to rapidly emulsify the oil and
therefore facilitate fast microbial growth.
 Advantages of biosurfactans includes low toxicity ,
biodegradability and ecological acceptability.
 Most known biosurfactants are glycolipids .
BIOSURFACTANTS

8. Three classes of Surface active compounds
are present in biosurfactants:
 LOW MOLECULAR WEIGHT SAC
 HIGH MOLECULAR WEIGHT SAC
 Amphiphilic polymers
 Polyphilic polymers
MICROBIAL SURFACE ACTIVE COMPOUNDS IN
BIOSURFACTANTS

9. MICROBIAL SURFACE ACTIVE COMPOUNDS
IN BIOSURFACTANTS
Classification of Biosurfactants
Glycolipids – Sophorolipids, Trehalolipids, and
Rhamnolipids
Lipopeptides and Lipoproteins
Fatty acids
Phospholipids
Neutral lipids
Polymeric biosurfactants
Particulate biosurfactants
Rhamnolipid Sophorolipid
Surfactin (Lipopeptide)
Trehalolipid

10. International Journal of
Molecular Sciences
ISSN 1422-0067

11. International Journal of
Molecular Sciences
ISSN 1422-0067

12. International Journal of
Molecular Sciences
ISSN 1422-0067

13. Advantages
Non-toxic or low in toxicity
 Biodegradable
 Wastes can be used as raw materials
Environmental compatibility
Vast diversity in structure
High selectivity
Biosurfactants can be produced using renewable resources
BIOSURFACTANTS

14. BIOSURFACTANT-PRODUCING
MICROORGANISMS
A number of microorganisms, such as fungi, yeasts, and bacteria,
feed on substances that are immiscible in water, producing and
using a surface-active substance (biosurfactant).
Pseudomonas
species
(Rhamnolipids)
Bacillus
subtilis(surfactin)
Candida bombicola
and Candida
lipolytica

15.  In a hydrocarbon dispersed aquatic medium there is
conversion of hydrophobic carbon hydrophlic
bacterial cell surface accepted form
 Rhodococcus sp.
 have high affinity to hydrocarbons.
 low levels of endogenous respiration,
 slow switching to a new substrate.
Cannot accumulate intracellular carbon pool
 Pseudomonas sp.
 have high endogenous metabolism activity,
easy switch to new carbon sources,
rapidly growing
synthesize bioemulsifiers..

16. International Journal of
Molecular Sciences
ISSN 1422-0067

17.  A class of pollutants facing particular attention today is
the polycyclic aromatic hydrocarbons (PAHs). Interest in the
biodegradation mechanisms and environmental fate of PAHs is
prompted by their ubiquitous distribution in the environment
and their deleterious effects on human health.
 Primary sources for PAH entries into the environment include
emissions from combustion processes or from spillage of
petroleum products. Pollution of soil by tar oil from coal
gasification facilities.
 Rhodococcus erythropolis has shown good solubilisation
capacity for hydrophobic compounds such as phenanthrene
and great potential in bioremediation of sites with PAH
contamination,

19.  Physicochemical properties surface activity of biosurfactants is
comparable with surface activity of synthetic surfactants:
 Example biosurfactants are able to reduce surface tension of water
to 29.0 mN/m (at the cmc), while Pluronic F-68 to 42.8, SDS to 28.6
and LAS to 31 mN/m ).
 Moreover, water in-oil emulsions of palm, crude, soybean, coconut
and olive oils with biosurfactants were comparably or even more
stable than that with synthetic surfactants. On the other hand, if oil
phase are short-chain hydrocarbons, the emulsions are less stable with
biosurfactants. Biosurfactants are characterized by smaller than for
synthetic surfactants critical micellar concentration (cmc) (0.07 and
0.12 g/l for biosurfactant rhamnolipid and Rokanol NL6,
respectively). Therefore, in spite of a little smaller solubilisation
efficiency (presented in a form of weight solubilisation ratio: 0.218
for biosurfactant and 0.277 for Rokanol NL6, (Pastewski et al.,
2008)), they are more efficient in washing out oil from the ground.
The maximal oil removal for biosurfactant solution was about
22%, while for synthetic surfactant 14%.

21. Oil Spill, Alaska
Oil shimmers among rocks on
Alaska's North Slope, a region where
rich reserves of both wildlife and
hydrocarbons have led to pitched
battles between environmentalists
and petroleum interests. Oil spills
wreak havoc on coastal plants and
marine animals. But high-profile
incidents, such as the 1989 Exxon
Valdez accident in Alaska, tend to
focus public attention on the issue of
ocean pollution. Single-hulled oil
tankers were outlawed in the U.S.
after that devastating spill.

22. Exxon Valdez Oil Spill
A pool of saffron-colored oil
paints swirls along Alaska's
shoreline following the
ExxonValdez oil spill in 1989.
Although it was not large
compared to other spills, the
Valdez oil spill was one of the
world's most ecologically
devastating disasters, spoiling
more than 1,200 miles (1,931
kilometers) of shoreline,
including three national parks,
three national wildlife refuges,
and one national forest.
Next

23. Disadvantages of biosurfactants
Concerning disadvantages, one of the problems is related
to large scale and cheap production of biosurfactants.
 Large quantities are particularly needed in petroleum and
environmental applications, which, due to the bulk use, may
be expensive. To overcome this problem, processes should be
coupled to utilization of waste substrates combating at the
same time their polluting effect, which balances the overall
costs.
Another problem may be encountered in obtaining pure
substances which is of particular importance in
pharmaceutical, food and cosmetic applications. Downstream
processing is involved with multiple consecutive steps.
Therefore, high yields and biosurfactant concentrations in
bioreactors are essential for their facilitated recovery and
purification.

27. CONCLUSION
The usefulness of biosurfactants in bioremediation is
expected to gain increasing importance in the future.
To date, biosurfactants are unable to compete
economically with the chemically synthesised
compounds in the market mainly due to their high
production costs and lack of comprehensive toxicity
testing.
CHALLENGES IN USING BIOSURFACTANTS
The first challenge will be to determine biosurfactant
compositions that can function most efficiently to
disperse the massive quantities of oil waste under a
range of marine conditions that include variations in
the Gulf temperature and oil compositions.
The second challenge is to encourage natural oil-
degrading marine organism at the spill site to attach to
the oil droplets formed by the biosurfactants and then
use the oil as a food source.
The third is to determine that all these things occur
quickly to protect the delicate balance present in
marine ecosystems.