Why Is Ammonification Vital in the Nitrogen Cycle?
Soil contains so many important elements like Carbon, Oxygen, Nitrogen, Sulphur and many more. Among them, Nitrogen is considered as one of the important elements. All these nutrients are consumed by plants but not directly. For example, plants are not able to consume atmospheric nitrogen directly. This atmospheric nitrogen needs to be converted into a simpler form for consumption. For this conversion few bacteria participate and convert atmospheric nitrogen into absorbable form and after this conversion, plants use this simpler form of nitrogen.
For all this conversion of nitrogen, there is a separate cycle called the Nitrogen cycle. The nitrogen cycle is a biogeochemical cycle which converts nitrogen into various simple forms by going through various sub-cycles like nitrification, assimilation, ammonification, denitrification.
Ammonification
Ammonification is a subpart of the Nitrogen cycle and by this process, organisms are able to consume Nitrogen for their survival. In this process, microorganisms like bacteria and other decomposing bacteria act in combination on dead organic matter to convert their nitrogen into simple ammonia form. This process of conversion of nitrogen into ammonia is known as ammonification. These simple forms of Nitrogen help organisms to survive by consuming them for their growth.
Steps Involved in Ammonification Process
Ammonification is a third step of the Nitrogen cycle. Under this process so many chemical reforms take place. In this ammonification process, NH2 groups are converted into (NH4+) and ammonia is the end product of the ammonification process. The substrates of the ammonification process are urea, uric acid and organic nitrogen of faeces.
After this conversion Ammonia can be assimilated and combined to form various amino acids which further play an important role in various metabolic processes. There are so many nitrogen-carrying compounds present in living organisms, some of them are proteins, nucleic acid, DNA, Vitamins, urea, etc.
Implications of Ammonification Process:
Some of the important roles of the ammonification process are listed below:
1. As nitrogen in any living organism is present in organic form and this form cannot be used directly. So, through the ammonification process, nitrogen is converted into ammonia which is further converted into ammonium by plants for absorbing them. Ammonia is an inorganic form of Nitrogen.
2. There are so many nitrogen-carrying compounds present in living organisms, some of them are proteins, nucleic acid, DNA, Vitamins, urea, etc.
3. During the ammonification process nitrogen present in dead and decaying parts of plants and any other organisms is converted.
4. Nitrogen in the ecosystem is present in organic form and conversion of this organic form into an inorganic form is necessary for the absorption of organic compounds into a simpler form.
5. There are many plants which survive on acidic soils and in such condition ammonification plays a crucial role in the absorption of nitrogen.
6. Addition of fertilizers to the soil leads to an increase of ammonia levels in the soil causing overgrowth of fungi sometimes which lead to an imbalance in the ecosystem.
What Do Bacteria Do During Ammonification?
When any living organism dies the nitrogen from their cells or tissues comes out in the form of nitrogen (organic form) like amino acids, DNA. Further various bacteria like fungi, prokaryotes and more work together to decompose the tissue and convert organic form nitrogen into inorganic form nitrogen. This inorganic form is used by each microorganism.
Examples of a few ammonifying bacteria are Bacillus, Proteus, Clostridium, Pseudomonas and Streptomyces.
Function of Ammonification:
Our atmosphere is composed of several gases out of which nitrogen has the highest percentage i.e 78%. But this nitrogen is not suitable for living beings as it is in organic form i.e. N2 and for this conversion only the ammonification process is mandatory. Through the ammonification process N2 (organic form) is converted into NH3 (inorganic form) which is necessary for plants. This inorganic form returned to the ecosystem and is suitable for all living organisms.
One Word Answer:
1. Which is the last product of the ammonification process?
Ans. Ammonia
2. Atmospheric nitrogen is in which form?
Ans. Organic
3. Which gas has the highest percentage in the atmosphere?
Ans: Nitrogen (78%)
FAQs on Ammonification Explained: Steps, Functions & Importance
1. What is the process of ammonification?
Ammonification is a vital decomposition process carried out by microorganisms in the soil and water. During this process, organic nitrogen, found in dead plants, animals, and their waste products (like proteins and nucleic acids), is converted into inorganic ammonia (NH₃). This ammonia then typically reacts with water in the soil to form ammonium ions (NH₄⁺), which can be utilised by plants.
2. What is the ecological importance of ammonification?
The primary importance of ammonification is its role in nutrient cycling. It unlocks nitrogen that is trapped in dead organic matter and returns it to the ecosystem in an inorganic, usable form. This process ensures a continuous supply of nitrogen for plants, which are the primary producers, thereby supporting the entire food web. Without ammonification, nitrogen would remain locked away, leading to depleted soil fertility and stunted ecosystem growth.
3. What are the main steps involved in the ammonification process?
Ammonification occurs in a few key steps after an organism dies or excretes waste:
- Decomposition of Organic Matter: Decomposer microbes like bacteria and fungi begin to break down complex organic molecules.
- Enzymatic Action: These microbes release enzymes such as proteases and nucleases, which break down proteins into amino acids and nucleic acids into nitrogenous bases.
- Deamination: The amino groups (-NH₂) are removed from the amino acids.
- Formation of Ammonia: This released amino group is then converted into ammonia (NH₃), which is the final product of ammonification. In the soil, it usually becomes the ammonium ion (NH₄⁺).
4. Which microorganisms are responsible for ammonification?
A wide range of decomposer microorganisms, often referred to as ammonifying bacteria and fungi, are responsible for this process. They are not a specialised group but rather a functional one. Common examples include bacteria from the genera Bacillus, Clostridium, and Proteus, as well as various species of fungi that thrive on decaying organic material.
5. Can you provide a real-world example of ammonification?
A classic example of ammonification can be observed in a compost pile or on a forest floor. When leaves fall from trees or an animal dies, decomposer bacteria and fungi colonise the organic matter. As they break down the proteins and other nitrogen-containing compounds in the dead material, they release ammonia. This is why a poorly aerated compost pile can sometimes have a sharp, distinct smell of ammonia, signifying that ammonification is actively occurring.
6. How does ammonification fit into the larger nitrogen cycle?
Ammonification is a crucial link in the nitrogen cycle that connects the pool of organic nitrogen (in biomass) with the pool of inorganic nitrogen (in soil). It follows nitrogen fixation (where atmospheric nitrogen is converted to ammonia) and the assimilation of nitrogen by organisms. The ammonium (NH₄⁺) produced during ammonification serves as the essential starting material for the next major step in the cycle: nitrification, where other bacteria convert it into nitrites and nitrates.
7. How is ammonification different from nitrification?
While both are key stages in the nitrogen cycle, they are fundamentally different processes:
- Starting Material: Ammonification starts with organic nitrogen (from dead matter). Nitrification starts with ammonium (NH₄⁺).
- End Product: Ammonification produces ammonia/ammonium (NH₄⁺). Nitrification produces nitrites (NO₂⁻) and then nitrates (NO₃⁻).
- Microorganisms: Ammonification is carried out by general decomposers (e.g., Bacillus). Nitrification is a two-step process carried out by specialised chemosynthetic bacteria like Nitrosomonas and Nitrobacter.
- Function: Ammonification recycles nitrogen from dead biomass, while nitrification converts it into the form most readily absorbed by plants (nitrates).
8. What would happen to an ecosystem if the process of ammonification stopped?
If ammonification were to stop, the consequences for any ecosystem would be catastrophic. Nitrogen, an essential element for life, would become trapped in dead organisms, fallen leaves, and waste products. The soil's supply of usable inorganic nitrogen would not be replenished. This would lead to a rapid decline in soil fertility, causing plant growth to halt. Consequently, herbivores would run out of food, and the entire food web would collapse due to a critical shortage of bioavailable nitrogen.
