Question

The process of conversion of nitrogen to ammonia by microbes is?
A. Nitrification
B. Denitrification
C. Nitrogen fixation
D. Haber’s process

Answer 1

Hint:One of the most significant nutrients required for the survival of living organisms is nitrogen. Nitrogen is abundant in the atmosphere but is largely inaccessible to most organisms in this form. Some microorganisms are capable of transfiguring atmospheric nitrogen to fixed nitrogen making it available to plants. Microorganisms such as Azotobacter, Clostridium, Pseudomonas, etc. are some examples of nitrogen-fixing microbes.

Complete answer: Nitrogen is present in the environment in the form of organic nitrogen, ammonium, nitrate, nitrite, nitric acid, nitrous oxide, or inorganic nitrogen gas. Organic nitrogen is either present in the form of living organisms or in the form of an intermediate product of organic matter decomposition. The nitrogen cycle includes the transformation of nitrogen from one form to another with the required assistance by microbes.
The process of conversion of molecular nitrogen present in the air into Ammonia or related nitrogenous compounds in the soil is known as nitrogen fixation. Free-living or symbiotic bacteria known as diazotrophs are involved in nitrogen fixation reaction. To produce ammonia, the nitrogenous enzymes present in these bacteria combine gaseous nitrogen with hydrogen. This is then converted by the bacterias into other organic compounds. A wide variety of bacteria and some Archaea have Mo-nitrogenase, which is a complex two-component enzyme that has multiple metal-containing prosthetic groups.

Therefore, the correct answer is option C. Nitrogen fixation.

Note: An example of symbiotic nitrogen-fixing bacteria is Rhizobium, which is usually situated in the root nodules of legumes such as peas and locust trees. These bacteria form a mutualistic relationship with the plant and produce ammonia in exchange for carbohydrates. Due to this, legumes are known to have often increased the nitrogen content of nitrogen-poor soil.