Definition of Nitrogen fixation
1. Noun. The assimilation of atmospheric nitrogen by soil bacteria and its release for plant use on the death of the bacteria.
Definition of Nitrogen fixation
1. Noun. (chemistry) ,(biochemistry) the conversion of atmospheric nitrogen into ammonia and organic derivatives, by natural means, especially such conversion, by microorganisms in the soil, into a form that can be assimilated by plants ¹
¹ Source: wiktionary.com
Medical Definition of Nitrogen fixation
1.
The incorporation of atmospheric nitrogen into ammonia by various bacteria, catalysed by nitrogenase.
This is an essential stage in the nitrogen cycle and is the ultimate source of all nitrogen in living organisms. In the sea, the main nitrogen fixers are Cyanobacteria.
There are several free living bacteria in soil that fix nitrogen including species of Azotobacter, Clostridium and Klebsiella. Rhizobium only fixes nitrogen when in symbiotic association, in root nodules, with leguminous plants. The oxygen sensitive nitrogenase is protected by plant produced leghaemoglobin and the plant obtains fixed nitrogen from the bacteria.
See: Frankia.
This entry appears with permission from the Dictionary of Cell and Molecular Biology
(11 Mar 2008)
Lexicographical Neighbors of Nitrogen Fixation
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