Bacteria plays an important role in:

Explanation

In nitrogen cycle :Nitrogen-fixing bacteria convert N2 to ammonia Nitrifying bacteria convert ammonia to nitrates and nitrites Denitrifying bacteria release the N2 back to the atmosphere by converting nitrates back to atmospheric nitrogen. In the carbon cycle, bacteria decompose dead organisms and release carbon back to the environment. In the phosphorus cycle, bacteria convert phosphate into the organic form so that it can be utilized by the plants.