The document outlines the key processes of nitrification and denitrification in the nitrogen cycle, highlighting their importance and differences. Nitrification converts ammonium into nitrate, which is essential for plant growth, while denitrification reduces nitrate back to atmospheric nitrogen, playing a crucial role in maintaining nitrogen balance. Overall, both processes are vital for ecological health and agricultural productivity.

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2. Content..
 Objective
 Introduction about Nitrogen and Nitrogen cycle.
 Nitrification.
 Major steps of Nitrification.
 Denitrification.
 Importance of Nitrification and Denitrification.
 Key difference between Nitrification and
Denitrification.
 Conclusion.
 References.
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3. Objective
 To identify the important roles and the
differences of nitrification and denitrification in
the nitrogen cycle.
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Introduction about Nitrogen and
Nitrogen cycle.
What is Nitrogen?
 Nitrogen is,
• The largest single source in the atmosphere.
(N2-78%)
• An element used to build DNA,RNA and
proteins,this is the building block of life.
 Most living organisms are unable to use nitrogen
as it exists in the atmosphere. (Why ???)
 It can be used by most living organism by travelling
through one of the four processes in the nitrogen
cycle.

5. Nitrogen cycle
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1) Nitrogen fixation
2) Ammonification
3) Nitrification
4) Denitrification

6. Plant absorb nitrates and grow
Ammonium (NH+
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Nitrosomonas
Ammonia change to nitrites(NO2
-)
Nitrobacter
Nitrifying bacteria in soil convert
nitrites to nitrates (NO3
-)
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Nitrification

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 The bacteria are autotrophic and the reaction is
performed under aerobic condition.
 The importance of this step in the nitrogen cycle is
the conversion of ammonia in to nitrate.
 As nitrate is the primary nitrogen source present
in the soil for the plant.

8. Nitrification is a two steps process.
1st step Ammonium oxidation
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Ammonia – oxidizing bacteria are involved,
Ex:- chemoautotrophs sp.
These microorganisms are growing with
ammonia as the energy and co2 as the main
carbon source.

9. These species are distributed in a great variety
of ,
soil
oceans
rivers
lakes
Brackish
environment
Sewage disposal
systems
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2nd Step - Nitrite oxidation
Nitrite oxidizing bacteria are found in aerobic, but
occasionally in anaerobic environments where
organic matter is mineralized.
They are found in the area where the ammonia
oxidizing bacteria are living other than that,
Inside stones and historical buildings
Inside corroded bricks
On concrete surfaces
Cooling towers and high way tunnels

11. How does nitrogen re enter the atmosphere in
the nitrogen cycle?
• This process called “Denitrification’’
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12. What is Denitrification (Important)
• Denitrification is convert Nitrate (N03
-) in the soil to atmospheric
Nitrogen (N2) replenishing the atmosphere.
• Many soil microorganisms are involving.( mostly heterotrophic
bacteria species)
• Denitrifying microbes require very low O2 concentration of less
than 10% .
Examples: Pesudomonas
Achromobacter
Micrococcus
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13. After Nitrification process
Nitrogen in atmosphere closes the Nitrogen cycle (N2)
Process of Denitrification
Nitrite (NO2
- )
Nitrate (N03
- )
Nitric Oxide ( NO)
Nitrous oxide (N2O )
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14. Importance of Nitrification and
Denitrification
Nitrification Denitrifation
• Preferred chemical form of nitrogen
uptake from soil or water.
• Produces accessible plant forms of
nitrogen
• Removes fixed from the ecosystem
• Enhance the greenhouse effect
• Provides nitrate to the plant, which
acts as the important nitrogen source
• Denitrification is used in waste water
treatment and is beneficial for aquatic
habitats
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15. Key Difference Between
Nitrification And Denitrification
Nitrification Denitrification
Meaning  The part of nitrogen cycle where
ammonium is convert into
nitrate.
 The level where reduction of
nitrate is made in to
nitrogen gas.
The process involves  Nitrifying bacteria like
Nitrobacter , Nitrosomonas
 Aerobatic.
 Grow slowly.
 Denitrifying bacteria like
spirillum, lactobacillus .
 Anaerobic.
 Grows rapidly.
PH and temperature  The process occurs at the pH
between 6.5 to 8.5 and
temperature between 16 to 35
degree C.
 The process occurs at the
pH between 7.0to 8.5 and
temperature between 26
to 38 degree C.
End product  Nitrate  Nitrogen
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Conclusion
 Nitrogen is the substantial part of the
atmosphere, as well as plants and animals
also.
 As nitrogen cannot be used directly and so is
transferred in through various sources.
 Nitrification and denitrification are two major
steps in the nitrogen cycle and found
variations in their products and needed.
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T A
H
N
K
Y O U
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