Nitrogen fixation is the process by which
nitrogen is taken from its natural, relatively inert molecular form (N
2) in the
atmosphere and converted into nitrogen compounds (such as
ammonia,
nitrate and
nitrogen dioxide).
[1]Nitrogen fixation is performed naturally by a number of different prokaryotes, including bacteria, actinobacteria, and certain types of anaerobic bacteria. Microorganisms that fix nitrogen are called diazotrophs. Some higher plants, and some animals (termites), have formed associations with diazotrophs.
Nitrogen fixation also occurs as a result of non-biological processes. These include lightning, industrially through the Haber-Bosch Process, and combustion.[2]
Biological nitrogen fixation was discovered by the Dutch microbiologist Martinus Beijerinck.
