1. MECHANISM OF AEROBIC &
AN-AEROBIC
BIODEGRADATION
PRESENTED BY:-
SUKHJEET KAUR
M.Sc. BT(H)3SEM
130181106
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2. CONTENT
Biodegradation
Types
Aerobic degradation
Mechanism of aerobic degradation
Anaerobic degradation
Mechanism of anaerobic degradation
Difference between aerobic and
anaerobic
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3. BIODEGRADATION
Biodegradation is a natural and
complex process of decomposition
facilitated by biochemical reactions
It is biological transformation of an
complex organic material to simpler by
micro organisms
Biodegradable matter is generally
organic material such as plant &
animal matter
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4. DEGRADATION TIME
PRODUCT TIME TO DEGRADE
APPLE CORE 1-2 months
GENERAL PAPER 1-3 months
CARDBOARD BOX 2 months
COTTON CLOTH 5 months
TIN CANS 50-100 months
ALUMINIUM CANS 150-200 months
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5. BIODEGRADEBILITY
Very easily degradable
Easily degradable
Potentially degradable
Very slowly degradable
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6. TYPES
AEROBIC BIODEGRADATION
AN-AEROBIC BIODEGRADATION
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7. AEROBIC
BIODEGRADATION
 It is the breakdown of organic
contaminants by micro organism when
oxygen is present
 Organic contaminants are rapidly
degraded under aerobic conditions by
aerobic bacteria called aerobes
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8. MECHANISM OF AEROBIC
DEGRADATION
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9. EXAMPLE:-
GRAM NEGATIVE STRAINS GRAM POSITIVE STRAINS
Pseudomonas spp. Nocardia spp.
Flavobacterium spp. Mycobacterium spp.
Xanthomonas spp. Arthrobacter spp.
Acinetobacter spp. Bacillus spp.
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10. AEROBIC DEGRADATION OF
BIOPOLYMERS
It mainly includes two steps:
1.Complex organic compounds
Exoenzyme
action
Simple adsorbable polymers
2. Simple polymers
respiration
Basic elements + energy
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11. AEROBIC BIODEGRADATION
OF CARBOHYDRATES
11
Lignin, cellulose, hemicellulose, starch,
glycogen
Hydrolysis (by respective enzymes)
Fructose,
cellobiose,pentoses
Pyruvate Fructose 1-
phosphate
Glucose
glycolysis fructokinase
glycolysis
CO₂+ water+ energy +growth
TCA cycle
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12. 12
AEROBIC DEGRADATION OF LIPIDS
Neutral fats,
Phospholipids,
Wax
Fatty acids
Fatty Acyl CoA
β - oxidation
Hydrolysis
Lipases,phospholipas
es
Activation
Acetyl coA
TCA
CYCLE
CO₂+ water+
energy +growth
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13. 13
AEROBIC DEGRADATION OF PROTEINS
Proteins
Hydrolysis (by Proteases)
Aminoacid
peptidases
Carboxylic acids of
AcetylCoA
Arg,His,Glu,Pro
Ala,Thr,Gly,Ser Phe,Tyr,Leu,Trp Phe,Tyr
2-Oxo glutarate Pyruvate AcetoacetylCo
A
Fumarate
CO₂+ water+
TCA cycle energy +growth
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14. AEROBIC DEGRADATION OF
HYDROCARBONS
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15. DEGRADATION OF AROMATIC
HYDROCARBONS
It can be converted to the natural
intermediates that is catechol and
protocatechuate
Some Gram negative bacteia have
plasmids that encode enzymes for
degradation of aromatics called TOL
plasmids
It mainly involves hydroxylation
catalysed by dioxygenase
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16. 16
Degradation
of Aromatic
hydrocarbon
s
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17. DEGRADATION OF
TOULENE
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18. AN-AEROBIC
BIODEGRADATION
Anaerobic digestion occurs when the
anaerobic microbes are dominant over
the aerobic microbes widely used to
treat wastewater sludge and
biodegradable waste because it
provides volume and mass reduction
e.g Clostridia, Eubacterium spp.
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19. PROCESS
There are four key biological and
chemical stages of anaerobic
degradation
Hydrolysis
Acidogenesis
Acetogenesis
Methanogenesis
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20. STAGES
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21. ORGANISMS INVOLVED
Acedogenesis-
Clostridium,Eubacterium,Ruminococc
u
Acetogenesis-
Syntrophobacter wolanii
Syntrophomonas wolfii
Methanogenesis- Methanothrix
 Methanosacenia
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22. ANAEROBIC
BIODEGRADATION OF
CARBOHYDRATES
22
Lignin, cellulose, hemicellulose, starch,
glycogen
Hydrolysis (by respective enzymes)
Monomers (Glucose, Pentoses,
Cellobiose)
Fermentation
Formate, Butyrate, Lactate, etc
Acetogenesis
Acetate
Methanogenesis
Methane + CO2
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23. ANAEROBIC DEGRADATION OF PROTEIN
23
Proteins
Hydrolysis (by Proteases)
Aminoacid
Deamination
Organic
acids
Fermentation
Acetate
NH
3
Formate, Butyrate, etc
Acetogenesis
Methanogenesis
Methane +
CO2
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24. ANAEROBIC DEGRADATION OF
LIPIDS
24
Neutral fats,
Phospholipids
Inositol, Glycerol,
GlucosFeermentation
Glycolipids Fatty Acids
β- Oxidation
Acetyl coA
Acetat
e Methanogenesis
Methane +
CO2
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25. ANAEROBIC DEGRADATION
OF AROMATIC
HYDROCARBONS
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26. ANAEROBIC DEGRADATION
OF XENOBIOTICS
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27. DEGRADATION OF
HERBICIDES
DIURON is a systemic herbicide
derived from urea, relatively persistent
in soil,
half-lives from 90 to 180 days.
It shows slight acute toxicity
It is a likely carcinogen
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28. Diuron has a very slow rate of natural
hydrolysis in a neutral solution at 25 C
However, when hydrolysis occurs the
degradation in water solution is an
irreversible reaction giving 3,4-DCA as
the only product
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29. ANAEROBIC DEGRADATION
OF DIURON
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30. Difference between aerobic and
anaerobic biodegradation
AEROBIC
 Most rapid and fast
degradation .
 No pungent gas
produced .
 More expensive
 Large disposable
waste generated.
 Microbes are
Xanthomonas,Coma
monas
ANAEROBIC
 Time consuming and
slow
 Pungent gas produced.
 Less expensive
 Less waste is
generated
 Clostridia ,Eubacteria
etc.
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31. REFERENCES
Introduction to environmental
biotechnology by A.K chatterji
A text book of environmental
biotechnology by Pradipta Mohaptra
www.ensobottles.com/.../Aerobic%20
Anaerobic%20Biodegradation
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