This document provides an overview of bioremediation of hydrocarbon pollution. It discusses various techniques used for hydrocarbon pollution removal and their disadvantages. It then describes bioremediation as a natural process that uses microorganisms to degrade hydrocarbons into less toxic forms. The document outlines different bioremediation strategies like bioaugmentation and biostimulation and notes advantages such as low cost and generating non-toxic byproducts. It also discusses using genetically engineered microorganisms and phytoremediation using plants. In conclusion, the document emphasizes the need for understanding biodegradation mechanisms to transform pollutants in less toxic forms using microorganisms and plants.

1. BIOREMEDIATION OF HYDROCARBON – A REVIEW
Name:-- Anwesha Banerjee.

2. Index
1. Introduction.
2. Hydrocarbon Pollution.
3. Effects of Hydrocarbon pollution.
4. Detrimental Effects on Humans.
5. Components of Hydrocarbon
Pollution.
6. Common Techniques : for removal
of hydrocarbon pollutants.
7. Disadvantages of Physico-
Chemical methods.
8. Bioremediation.
9. Bioremediation : Contd.
10. Strategies of Bioremediation.
11. Advantages of bioremediation.
12. Disadvantages of bioremediation.
13.Bioremediation By Genetically
Engineered Microorganisms.
14. Phytoremediation.
15.Mode of action : phytoremediation
16. Parameters of phytoremediation.
17. Pollution in India
18. Conclusion.
19. Acknowledgement.
20. Reference.

3. Introduction:
Hydrocarbons are compounds made of carbons and hydrogen, The majority of
hydrocarbons found on Earth naturally occur in crude oil, they are major energy source
in today’s world.
Increase in industrialization and development has seen an increased used of
hydrocarbon containing fuel like petroleum and its products, diesel, natural gas.
Due to this unprecedented increase in using fuels, accidents and pollution related to
this is increasing at an alarming pace.
In India recent oil spill incident occurred in Mumbai 2010, which left vast areas of the
Arabian sea polluted with leaked oil and toxic waste of about 100 out of 250 containers
were dumped in the sea from the ship.

4. Hydrocarbon Pollution
Pollution due to hydrocarbons have toxic, fatal and
disastrous effect on the aquatic, terrestrial as well as on the
atmosphere. The major reasons for pollution are Oil spills in
oceans, leakages in pipelines carrying crude oil and gas
exploration activities, and accidents during production,
refining, transport and storage of petroleum and its by-
products.
Every year about 35 million barrels of oil are ferried across
the oceans, making the aquatic environment vulnerable to
pollution from oil spills, leakages that threaten the aquatic or
marine life all over.
Land pollution due to effluents from industries; untreated,
toxic waste from refineries are one of the main causes of
ground water contamination, overall reduced productivity of
agricultural land.

5. Effects Of Hydrocarbon Pollution
EFFECTS
OF
POLLUTIO
N
GLOBAL WARMING.
ACID RAIN
OZONE
DEPLETION
LOSS OF SPECIES
DIVERSITY
.(ENDANGERED)BOTH
FLORA AND FAUNA
ECONOMIC LOSS.
HUMAN HEALTH
HAZARD AND
DISEASES.

6. Detrimental Effects On Humans:
Aromatic hydrocarbons may lead to cancer.
Inhalation of hydrocarbon can cause irritation in the respiratory tract ,
they can cause onset of asthma and other allergies.
Most hydrocarbons are carcinogenic to lungs.
PAHs can cause prenatal defects, reduced birth weight , developmental
deficits

7. Components Of Hydrocarbon
Pollution:
Alkanes
Aromatic Hydrocarbons
Phenol
PolyCyclic Aromatic Hydrocarbon(PAH)

8. Common Techniques : For Removal Of Pollutants:
 To remove the pollutants from the contaminated site of soil and water several
physico-chemical methods have been developed for the decontamination of the site.
Such methods are not only highly expensive but also labor intensive and there is an
inherent risks of aggravating the situation and spreading of the pollution.
Common technologies used are evaporation, burying, dispersion and washing
(Das & Chandran, 2010), but as is the problem with these techniques they often lead to
incomplete decomposition of the pollutants. Thus a process of natural, yet simple and
cost effective method of hydrocarbon removal is desired in today’s world.
The techniques used to remove oil spill contaminations are land-fill burials and
incinerations for safe disposal others were pyrolysis, gasification but in most cases
the by-products have some negative shock on the environment.

9. Disadvantages of Physico-Chemical Methods
They are expensive.
Labor intensive.
High chances of contaminant
leaching.
Spreading and aggravating the
site of pollution.
Often lead to incomplete
decomposition of pollutants.

10. BIOREMEDIATION:
Bioremediation is the process of utilizing living organisms, microorganisms to
degrade pollutants and contaminants from the environment and transform them into less
toxic form.
Bioremediation of hydrocarbon pollution can be done by both microorganisms and
plans (phytoremediation).
Bioremediation is based on the ability of micro-organism to degrade the hydrocarbons
into components that can be taken up by other micro-organisms as nutrient source or
can be safely returned to the environment. Degraded organic components are converted
into water, carbon-dioxide and other inorganic compounds.

11. BIOREMEDIATION : Contd.
There are three types of bioremediation strategies:
(i) In situ Bioremediaton.
(a) Bioventing.
(b) Biosparging.
(c) In situ Biodegradation.
(ii) Ex situ Bioremediation.
[a] Biopiles.
[b] Land Farming.
[c] Composting.
[d] Anaerobic degradation .
(iii) Bioreactors.

12. Strategies Of Bioremediation:
Bioaugmentation – where known oil degrading bacteria are added to help and
supplement the existing microbial population. In this method microorganisms that can
either be indigenous or genetically modified, are added to the site of contamination and
bioremediation begins. This method is very effective where the native soil
microorganism are unable to degrade the hydrocarbon pollutants.
Biostimulation – where the indigenous microorganism are stimulated to grow with
addition of growth factors like nutrients. Sometimes effective remediation is not
possible for indigenous microorganisms in normal circumstances thus they have to be
stimulated by optimizing the surrounding environment of the contaminated site. So by
adding nutrient, oxygen, electron acceptor the existing population is stimulated. The
stimulants are added to the subsurface through injection wells.

13. Advantages of Bioremediation
Bioremediation is a natural process, it is widely accepted by public as a effective way
to remove hydrocarbon waste.
The biodegraded compounds are harmless and can be incorporated in the environment
(carbon dioxide, water and biomass.)
Bioremediation helps to degrade the pollutants on the site without causing additional
hazard.
It is relatively inexpensive than other techniques used for clean-up of hazardous waste
products.

14. Disadvantages Of Bioremediation.
Bioremediation process is limited to compounds that are biodegradable.
Growth of microorganisms for the bioremediation of the pollutant site is often very
specific and demanding
Sites containing many different types of contaminants in various phases (solid, liquid
,gas ) which needs special treatment.
It is time consuming process and may need extra pre-treatment before they can be
degraded by microorganisms (excavation, incineration). Which makes this process
tedious.

15. Bioremediation by Genetically Engineered Microorganisms:
In most common circumstances in a oil polluted sites indigenous microorganism are
unable or do not act their full capability to degrade the pollutants, thus the need of
genetically engineered or modified microorganisms (GEMs)
They can increase the yield of breakdown of the pollutants .
In this technique appropriate genes for production of a protein or enzymes are inserted into
the microorganism genome or as a plasmid, the gene when it is expressed produces those
enzymes and proteins which degrade the contaminant (jain et al, 2010c).
In 1971, General Electric and one of its employees, Anand Mohan Chakrabarty applied for
a US patent on a genetically engineered Pseudomonas sp - a microbe that has a voracious
appetite for oil. The first GEM for oil degradation. This new microorganism had plasmids
containing genes for Octane, Toluene, Naphthalene degradation.
The first GEM to be released for field trial was designed by University of Tennessee
in collaboration with Oak Ridge National Laboratory (Sayler et al., 1999), they released
Pseudomonas fluorescens (strain HK44GEM) in a contaminated soil site, this strain
was incorporated with Vector pUTK21 which is a naphthalene catabolic plasmid(King
et al., 1990).

16. Phytoremediation: Bioremediation By Plants
Phytoremediation is a new technology which utilizes living green plants for removal,
degradation or containment of pollutants in soil, water(both surface and groundwater),
sludge and sediments.
It is a low cost cleanup technique by using solar energy via plants.
It is very useful for sites that are shallow with low levels of pollutants and sites where
vegetation is used as a final closure to the polluted site.
Phytoremediation is gaining popularity due to its aesthetic advantages and long term
applicability where maintaining microorganisms for a long term is not feasible.

17. Mode of Action: Phytoremediation

20. Conclusion:
•Hydrocarbon pollution removal is a real problem
•A better understanding of the biodegradation mechanisms of the microorganisms is
needed and is of utmost significance that will help transform pollutants into less toxic
and harmful by-products
• Microorganisms aided elimination of spilled oil from soil and water surfaces and sub-
surfaces is a very cost effective and simple process that can be popularized for
bioremediation.
• Plants also contribute towards bioremediation of hydrocarbon pollutions by utilizing
the components of pollutants as a source of energy for itself and also broken down
pollutants into less toxic form are taken up by rhizosphere microorganisms.
• Genetically modified microorganisms that can help to remove petroleum, naphthalene,
toluene, benzene and other contaminants, forms a newer aspect of research with broad
implications.

21. Acknowledgement:
I would like to express my special thanks of gratitude to my Head Of
Department Dr. Sandhimita Mondal as well as my project mentor Atanu
Roy, for helping me in this review, on the topic Bioremediation of
Hydrocarbons –A review. also my teachers Suvakshan Dutta and
Debojyoti Roychowdhury for helping me in this project
Secondly I would also like to thank my parents and friends who helped
me a lot in finalizing this review paper.

22. Reference
Microbial Degradation of Petroleum Hydrocarbon Contaminants: An Overview
Nilanjana Das and Preethy Chandran Environmental Biotechnology Division, School of
Biosciences and Technology, VIT University, Vellore, Tamil Nadu 632014, India.
Jain P.K., Gupta V.K., Gaur R.K, Bajpai V., Gautam N. and Modi D.R.
(2010c),Fungal Enzymes: Potential Tools of Environmental Processes. In: Fungal
Biochemistry and Biotechnology, Gupta, V.K., Tuohy M. and Gaur R.K. (Eds.). LAP
Lambert Academic Publishing AG and Co. KG, Germany, pp 44-56.
King J.M.H., DiGrazia P.M., Applegate B., Burlage R.and Sanseverino J.
(1990), Rapid, sensitive bioluminescent reporter technology for naphthalene
exposure and biodegradation. Science, 249, 4970, pp 778-781.
Chakrabarty, A. M., and I. C. Gunsalus. 1970. Transduction and genetic homology
between Pseudomonas species putida and aeruginosa. J. Bacteriol. 103:830-832.

23. References : Contd.
Chakrabarty, A. M., C. F. Gunsalus, and I. C. Gunsalus. 1967. Transduction and the
clustering of genes in the fluorescent pseudomonads. Proc. Nat. Acad. Sci. U.S.A.
60:168-175
Chakrabarty, A. M. 1972. Genetic basis of the biodegradation of salicylate in
Pseudomonas. J. Bacteriol. 112:815-823.
Sayler G.S. and Ripp S. (2000), Field applications of genetically engineered
microorganisms for bioremediation processes. Current Opinion in Biotechnology,
11(3), pp 286–289.
Sayler G.S., Cox C.D., Burlage R., Ripp S.and Nivens D.E. (1999), Field Application
of a Genetically Engineered Microorganism for Polycyclic Aromatic Hydrocarbon
Bioremediation Process Monitoring and Control. In: Novel Approaches for
Bioremediation of Organic Pollution, Fass, R., Flashner Y. and Reuveny S.
(Eds.).Kluwer Academic/Plenum Publishers, New York, pp 241-254.