Mechanism of aerobic & an aerobic biodegradation

MECHANISM OF AEROBIC &

AN-AEROBIC

BIODEGRADATION

PRESENTED BY:-

SUKHJEET KAUR

M.Sc. BT(H)3SEM

130181106

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CONTENT

Biodegradation

Types

Aerobic degradation

Mechanism of aerobic degradation

Anaerobic degradation

Mechanism of anaerobic degradation

Difference between aerobic and

anaerobic

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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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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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BIODEGRADEBILITY

Very easily degradable

Easily degradable

Potentially degradable

Very slowly degradable

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TYPES

AEROBIC BIODEGRADATION

AN-AEROBIC BIODEGRADATION

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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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MECHANISM OF AEROBIC

DEGRADATION

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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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AEROBIC DEGRADATION OF

BIOPOLYMERS

It mainly includes two steps:

1.Complex organic compounds

Simple adsorbable polymers

2. Simple polymers

Basic elements + energy

Exoenzyme

action

respiration

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AEROBIC BIODEGRADATION

OF CARBOHYDRATES

11

Lignin, cellulose, hemicellulose, starch,

glycogen

Fructose,

cellobiose,pentoses

Pyruvate Fructose 1-

phosphate

Glucose

glycolysis fructokinase

Hydrolysis (by respective enzymes)

glycolysis

CO₂+ water+ energy +growth

TCA cycle

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AEROBIC DEGRADATION OF LIPIDS

Neutral fats,

Phospholipids,

Wax

β - oxidation

Fatty Acyl CoA

Fatty acidsHydrolysis

Lipases,phospholipas

es

Activation

Acetyl coA

TCA

CYCLE

CO₂+ water+

energy +growth

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Proteins

Carboxylic acids of

Aminoacid

AcetylCoA

peptidases

Hydrolysis (by Proteases)

Arg,His,Glu,Pro

AEROBIC DEGRADATION OF PROTEINS

Ala,Thr,Gly,Ser Phe,Tyr,Leu,Trp Phe,Tyr

2-Oxo glutarate Pyruvate AcetoacetylCo

A

Fumarate

CO₂+ water+

energy +growth TCA cycle

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AEROBIC DEGRADATION OF

HYDROCARBONS

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DEGRADATION OF AROMATIC

HYDROCARBONSIt 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

Degradation

of Aromatic

hydrocarbon

s

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DEGRADATION OF

TOULENE

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AN-AEROBIC

BIODEGRADATIONAnaerobic 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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PROCESS

There are four key biological and

chemical stages of anaerobic

degradation

Hydrolysis

Acidogenesis

Acetogenesis

Methanogenesis

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STAGES

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ORGANISMS INVOLVED

Acedogenesis-

Clostridium,Eubacterium,Ruminococc

u

Acetogenesis-

Syntrophobacter wolanii

Syntrophomonas wolfii

Methanogenesis- Methanothrix

Methanosacenia

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ANAEROBIC

BIODEGRADATION OF

CARBOHYDRATES

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Lignin, cellulose, hemicellulose, starch,

glycogen

Acetogenesis

Monomers (Glucose, Pentoses,

Cellobiose)

Formate, Butyrate, Lactate, etc

Fermentation

Hydrolysis (by respective enzymes)

AcetateMethanogenesis

Methane + CO2

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ANAEROBIC DEGRADATION OF PROTEIN

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Proteins

Deamination

Aminoacid

Acetate

Hydrolysis (by Proteases)

Organic

acids

NH

3

Formate, Butyrate, etc

Fermentation

Acetogenesis

Methanogenesis

Methane +

CO2

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ANAEROBIC DEGRADATION OF

LIPIDS

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Neutral fats,

Phospholipids

Fatty AcidsGlycolipids

Inositol, Glycerol,

GlucoseFermentation

β- Oxidation

Acetyl coA

Acetat

e Methanogenesis

Methane +

CO2

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ANAEROBIC DEGRADATION

OF AROMATIC

HYDROCARBONS

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ANAEROBIC DEGRADATION

OF XENOBIOTICS

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DEGRADATION OF

HERBICIDESDIURON 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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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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ANAEROBIC DEGRADATION

OF DIURON

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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,Comamonas

ANAEROBIC

Time consuming and slow

Pungent gas produced.

Less expensive

Less waste is generated

Clostridia ,Eubacteria etc.

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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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