Nitrification is the natural process carried out by nitrifying bacteria. It is an essential step in the nitrogen cycle in soil.
Nitrification is the natural process that occurs in the environment by specialised autotrophic bacteria. During this aerobic process, ammonia is converted to nitrites (NO2-) and then nitrates (NO3-).
A group of specialised gram-negative, rod-shaped chemoautotrophic bacteria are called Nitrosomonas. Nitrosomonas is a rod-shaped genus of gram-negative, chemoautotrophic bacteria. These bacteria are involved in converting ammonia into nitrates.
Explore more: Gram-Negative Bacteria
Process of Nitrification
Nitrification is a microbial process carried out by Nitrosomonas. Reduced nitrogen compounds are sequentially oxidised to nitrite and nitrate in this biological process.
Two groups of autotrophic nitrifying bacteria primarily accomplish the nitrification process. The conversion of ammonia to nitrate is completed fundamentally by soil-living bacteria and other nitrifying bacteria.
Along with other genera, including Nitrosococcus and Nitrosospira, Nitrosomonas is the most commonly distinguished genus associated with this first step of Nitrification.
Step – 1
In the initial stage of Nitrification, ammonia is oxidised to nitrite in the presence of ammonia-oxidising bacteria. The reaction is as follows:
Ammonia (NH3) + Oxygen (O2) → Nitrogen Dioxide (NO2)- + 3 molecules of Hydrogen (3H+) + 2 electrons
Step – 2
In the second stage of Nitrification, nitrite is oxidised to nitrate in the presence of nitrite-oxidising bacteria. The reaction is as follows:
Nitrogen Dioxide (NO2)- + Water (H2O) → Nitrate (NO3)- + 2 molecules of Hydrogen (2H+) + 2 electrons
Nitrobacter is the commonly distinguished genus, which plays an essential role in this second step of Nitrification. Other genera, including Nitrospina, Nitrospira and Nitrococcus, can also oxidise nitrite autotrophically.
Also Refer: Denitrification.
Factors Affecting the Nitrification Process
Several environmental factors affect the rate of nitrification reaction. These environmental factors include:
- pH
- Temperature
- Loading rate
- Type of the media
- Depth of the filter
- Dissolved oxygen
- Presence of inhibitors
- Wastewater BOD -Biochemical Oxygen Demand
This article is a brief introduction to Nitrification and its process. Stay tuned to BYJU’S Biology for more information on Nitrification, Nitrogen cycle and other related topics.
Related Links:
- Nitrogen Cycle
- Nitrogen Fixation And Nitrogen Metabolism
- Difference Between Nitrification and Denitrification
Frequently Asked Questions on Nitrification
What is Nitrogen fixation?
The natural process of converting N2 to ammonia is known as nitrogen fixation.
Which bacterium is involved in converting nitrite into nitrate?
Nitrobacter is involved in converting nitrite into nitrate through an oxidation reaction.
What is Nitrification?
Nitrification is an essential step in the nitrogen cycle in soil.
In this natural process, ammonia is converted into nitrate by bacterial species present in the soil.
The reaction involved in the process of Nitrification is as follows:
2NH4+ + 3O2 → 2NO2– + 4H+ + 2H2O
2NO2– + O2 → 2NO3–
What is Denitrification?
Denitrification is the process of reducing the nitrates present in the soil
back into inert nitrogen gas. The process is carried out during the absence of oxygen by bacterial species such as Thiobacillus and Pseudomonas.
What is Nitrogen Fixation?
Nitrogen fixation is a biological process in which the nitrogen gas is converted into a usable form for plants and other microbes. In this process, nitrogen gas present in the atmosphere is converted into ammonia and other related nitrogenous compounds.
What is the importance of nitrogen?
Nitrogen is an essential component of all life, which also forms cellular components necessary for all forms of life. It is a significant constituent of biomolecules, such as nucleic acids and proteins.
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