What is nitrogen fixation?

Nitrogen fixation is the biochemical process in which atmospheric nitrogen gas (N2) is converted into ammonia (NH3) by specific organisms, such as certain bacteria and archaea. This process is crucial for ecosystems because most organisms cannot use nitrogen in its gaseous form. By transforming nitrogen into ammonia, which can then be assimilated into organic compounds by plants, nitrogen-fixing organisms play a vital role in the nitrogen cycle.

This process often occurs in the root nodules of leguminous plants, where symbiotic bacteria, such as Rhizobium, facilitate the conversion. The ammonia produced can further be used by plants to synthesize amino acids and nucleic acids, which are fundamental for growth and development. Thus, nitrogen fixation is a key mechanism that enables the transfer of nitrogen from the atmosphere into biological systems, supporting life on Earth.