Hydrocarbon are major constituents of crude oil and petroleum. They can be biodegraded by naturally-occurring microorganisms in freshwater and marine environments under a variety of aerobic and anaerobic conditions. The ability of microorganisms - bacteria, archaea, fungi, or algae - to break down hydrocarbons is the basis for natural and enhanced bioremediation. To promote biodegradation, amendments such as nitrogen and phosphorous fertilizer are often added to stimulate microbial growth and metabolism

1. ‘BIODEGRADATION OF
HYDROCARBON’
Dr. Rachana Choudhary
Asstt. Prof.(MICROBIOLOGY)

2. SYNOPSIS
 INTRODUCTION.
 BIODEGRADATION PROCESS.
 MICROBES INVOLVED.
 REACTIONS IN BIODEGRADATION PROCESS.
 BIODEGRADATION OF HYDROCARBONS.
a) aromatic hydrocarbon.
b) polycyclic hydrocarbon.
c) halogenated hydrocarbon.
 FACTORS AFFECTING BIODEGRADATION.
 GENETIC ENGEENERING FOR BIODEGRADATION.
 CURRENT STATUS
 CONCLUSION.
 REFERENCE.

3. INTRODUCTION
Biodegradation is a phenomena of biological
transformation of organic compounds by
living organisms where as,
Biotransformation
Means incomplete biodegradation of organic
compounds.

4. What is xenobiotic
compound?
means Xenos means (foreign) so
,it refers to un natural foreign
and synthetic chemicals such as
pesticides ,herbicides
,refrigerants
solvents and other organic
compounds.

5. Properties of xenobiotic
compounds.
 They become recalcitrant i.e resist
biodegradation and persist in
environment.
 Highily stable.
 Insoluble in water or adsorbed to
external matrices.
 Larger molecular size.
 Lack of permease needed for transport
into microbial cells.

6. BIOTRANSFORMATION
MINERALIZATION ACCUMULATION POLYMERIZATION
XENOBIOTICS
FATE OF XENOBIOTIC
COMPOUNDS

7. BIODEGRADATION PROCESS
Organic
molecules cell Co2 ,H2o
ph
Inorganic
nutrients
temp
Other metabolic
products
Molecular oxygen New cells

8. LIST OF SOME XENOBIOTIC
COMPOUNDS.
 DICHLOROBENZENE
 POLYCYCLIC AROMATIC
HYDROCARBIN.
 DDT
 ALDRIN
 CARBON TETRECHLORIDE.
 BHC
 HEXACHLOROETHANE

9. MICROBES USED IN
BIODEGRADATION
CHEMICALS MICROBES
HYDROCARBONS Pseudomonas,Nocardia,Art
hrobacter,Mycobacterium.
PCBS Pseudomonas,Candida,Alca
ligens.
PHENOLICS Pseudomonas,Flavobacteri
um,Trichosporum,Bacillus,A
spergillus.
POLY CYCLIC AROMATIC
COMPOUNDS
Arthrobacter,Nocardia,Alcal
igens.

10. METABOLIC EFFECT OF
MICROORGANISMS ON
XENOBIOTICS
 DETOXIFICATION
 ACTIVATION
 DEGRADATION
 CONJUGATION

11. TYPES OF REACTIONS
INVOLVED IN
BIODEGRADATION
 AEROBIC DEGRADATION.
ANAEROBIC DEGRADATION.
SEQUENTIAL DEGRADATION.

12. Hydrocarbon degrades as
follows:
HYDROCARBON AICOHOL
ALDEHYDE
FATTY ACID
FURTHER
METABOLIZED

13. BIODEGRADATION OF
HYDROCARBON
Hydrocarbons mainly pollutants from oil refineries
and oil spills.it can be degraded by consortium
or cocktail of microorganisms.
eg. Pseudomonas,
Corynebacterium,Arthrobacter etc.

14. AROMATIC HYDROCARBON
 Through aerobic and process.
 Important micro organism Pseudomonas.
Biodegradation of AH require sequence
of reaction---
 1) Removal of side chain
 2) Opening of benzene ring

16. CATECHOL AND PROTOCATECHUATE
ORTHO CLEAVAGE META CLEAVAGE
ACETYL-CoA
PYRUVATE
& ALDEHYDE.

18. POLYCYCLIC HYDROCARBON
 Contain two or
more rings.
 1 terminal ring
attached by
deoxygenase.
 Other ring is
catabolized.

20. FEATURES OF DEGRADATION
 Amide, ester or ether bonds are 1st
attacked &
further degradation of the products so
generated take place.
 If these bonds are absent or in accessible,
aliphatic chain are degraded.
 If the aliphatic chains are branched, the
aromatic components of complex molecular
may be may be attached.

21. DEGRADATION OF POLYCYCLIC
HYDROCARBON

22. BIODEGRADATION HOLOGENATED
AROMATIC COMPOUNDS
 Rate of the degradation is inversely related
to no of halogen atoms that are originally
presents on target molecule.
 Compounds which higher number of halogen
less easily degrade.
Involves two steps---
 1) Elimination of halogen group.
 Degradation of non halogenated product
molecule.

25. GENETIC ENGINEERING AS AN
EFFICIENT STEPS FOR
BIODEGRADATION
1) genetic manipulation by plasmid transfer
 1st
successful develop of new stain of
bacterium (Pseudomonas) by manipulation of
plasmid transfer was done by Chakrabarty &
co worker in 1970.
 Used different plasmid & constructed new
bacterium known as SUPER BUG
 Degrade camphor, octane, xylene &
naphthalene.

26. CREATION OF SUPERBUG

27. XENOBIOTIC AND THE
PLASMID CONTANING GENE
xenobiotic Name of plasmid in
pseudomonas
NAPTHELENE NAH
XYLENE XYL
XYLENE & TOULENE TOL,PWWO,XYL-K
SALICILATE SAL

28. CURRENT STATUS
 Pseudomonas putida:
1. It has been found to be useful in
detection of certain chemicals,such as
land mines.
2. P.putida is utilized as a way of detecting
land mines form soil contents.
3. It is found that there is a linkage
between the bacterias ability to degrade
TNT & explosive compound found in land
mines.

29.  Nitrosomonas europea:
1. It has nitrogen oxidizing properties.
2. Its metabolism has been studied under
ammonia rich conditions and is recognized
as limiting reactants in the conversion of
ammonia.
 Methylibium petroleiphilum:
1. it has ability to completely mineralize methyl
tert - butyl ether (MTBE) ,a gasoline additive.
2. It is capable of consuming diverse range of
gasoline derivatives as its sole carbon
source.

30. CONCLUSION
Biological degradation or
simply degradation is considered as a
phenomenon of biological transformation
of organic compounds by living organisms
particularly microbes.
microbial degradation of
organic compounds include processes of
aerobic and anaerobic degradation.

31. REFERENCE
Introduction Microbiology by-Brooke
Principle of Biochemistry by-
Nelson Cox & Leninger
Principle of Microbiology- Prescott 7th
addition

32. THANK YOU