Question

Explain briefly the role of bacteria in nitrogen fixation.

Answer 1

Role of bacteria in nitrogen fixation:

1. Nitrogen-fixing bacteria fix atmospheric nitrogen to ammonia and then convert it into nitrites and nitrates which can then be taken up by plants.
2. This process is called biological nitrogen fixation.
3. Nitrogen-fixing bacteria may be free-living or symbiotic.
4. Rhizobium is an example of symbiotic bacteria which infects root hairs and gets entry into the cortex.
5. Azotobacter and Clostridium are free-living bacteria that live in the soil and fix nitrogen by converting it into ammonia.