Question

Role of microorganisms in nitrogen cycling

Answer 1

Fix nitrogen into ammonia with the help of nitrogenase enzyme which is exclusively present in prokaryotics

Answer 2

There are four main parts of the nitrogen cycle and bacteria play a role in all of them. Bacteria help in nitrogen fixation, either as free-living entities or through symbiotic relationships with animals and plants (such as legumes). Another example is cyanobacteria. Bacteria break down the proteins contained in the bodies of plants and animals into ammonia through the process of decay. The next step in the nitrogen cycle is nitrification, which is carried out (in steps) by two nitrifying bacteria: nitrosomonas and nitrobacter. The former converts ammonia to nitrite, while the latter converts nitrite to nitrates. The final step is denitrification, which breaks down nitrates into nitrogen and replenishes the atmosphere. This step is carried out by denitrifying bacteria, such as anammox or ammonia oxidizing bacteria.

Thus, bacteria are key to nitrogen cycle.

Hope this helps.