Question

Name a biological process of nitrogen fixing bacteria present in soil.

Answer 1

Process of nitrogen-fixing bacteria:

1. Nitrogen fixation is a biological process that involves nitrogen-fixing bacteria in the soil converting nitrogen molecules in the air into nitrates and nitrites.
2. Plants cannot access nitrogen since it is an inert gas.
3. Plants get nitrogen from the soil and use it in the protein synthesis process.

Steps in the nitrogen cycle are :

Biological Nitrogen fixation:

1. The conversion of atmospheric, industrial, or biological nitrogen into such usable forms which can be utilized by living organisms is called biological nitrogen fixation.
2. Atmospheric Nitrogen fixation: It takes place through photochemical and electrochemical, reactions due to lightning and thunderstorms.
3. Biological Nitrogen fixation: It takes place through nitrogen-fixing bacteria such as Azotobacter, Azospirillum, and Algae such as Anabaena.
4. Industrial Nitrogen fixation: It takes place in industries at high temperatures and high pressure.

Assimilation:

The nitrates and nitrites are absorbed by green plants to produce the organic compounds of nitrogen.

Ammonification:

The decomposition of proteins of dead animals and plants to ammonia in the presence of ammonifying bacteria such as Bacillus ramosus and Bacillus vulgaris.

Nitrification:

1. The process of oxidation of ammonia into nitrites and nitrates in the presence of nitrifying bacteria such as Nitrosomonas and Nitrobacter.
2. The ammonia is first oxidized into Nitrite in the presence of Nitrosomonas bacteria and this nitrite is further oxidized to Nitrate in the presence of Nitrobacter bacteria.

Denitrification:

The process of conversion of nitrates and nitrites into molecular nitrogen in the presence of denitrifying bacteria such as Thiobacillus denitrificans