Denitrifying bacteria
3481221
218861167
2008-06-12T14:12:15Z
195.195.250.5
{{Unreferenced|date=April 2008}}
'''Denitrifying bacteria''' form a necessary part of the process known as [[denitrification]] as part of the [[nitrogen cycle]], their primary purpose being to [[metabolism|metabolise]] [[nitrogenous]] [[Chemical compound|compounds]], with the assistance of the ''nitrase reductase'' [[enzyme]], to turn [[oxide]]s back to nitrogen gas or nitrous oxides for energy generation. This process takes place only in the absence of [[oxygen]], as most denitrifying bacteria are essentially [[Anaerobic organism|anaerobic]] and the ''nitrase reductase'' can only be synthethised under anaerobic circumstances. This is the main reason why denitrification mostly occurs in the deep substrata of the [[soil]], or in areas of [[stagnant water]].
This process of denitrification lowers the fertility of the soil and thus is less common in areas where the land is rather well-[[Cultivation|cultivated]]. But this loss of nitrogen to the atmosphere can eventually be regained via introduced food and water, as part of the nitrogen cycle. Some nitrogen may also be [[nitrogen fixation|fixated]] by species of [[nitrifying bacteria]] and the [[cyanobacteria]].
Denitrification also becomes the key pathway for [[dissimilative nitrate reduction|dissimilation]], which is the process in which [[nitrates]] are reduced from the soil, the former being highly [[toxic]] for living organisms. Unlike its antithesis, denitrification tends to produce large amounts of [[by-product]]s.
The most common denitrification process is basically outlined below, with the nitrogen oxides being converted back to gaseous nitrogen (as opposed to that of nitrifying bacteria):
2NO<sub>3</sub><sup>-</sup> + 10e<sup>-</sup> + 12H<sup>+</sup> → N<sub>2</sub> + 6H<sub>2</sub>O
As can be seen, the result is one molecule of nitrogen (consisting of two atoms) and six molecules of water.
Denitrifying bacteria themselves include several species of ''pseudomonas'', ''alkaligenes'' and ''bacillus''. By their activity the losses of nitrogen into the atmosphere is roughly balanced by that which is released into the soil by nitrifying bacteria, forming the relatively reliable cycle.
===Denitriying bacteria===
A Group of [[bacteria]] that reduce [[nitrates]] or [[nitrites]] to nitrogen-containing gases.
Potential examples include''[[Thiobacillus]] denitrificans, [[Micrococcus]] denitrificans/''Paraoccus denitrificans'' and [[Pseudomonas]]''. This is important as it allows Nitrogen to cycle (see [[Nitrogen cycle]]) back into the [[atmosphere]].
These bacteria have also been implicated in depletion of soil fertility, and thereby agricultural productivity.
==See also==
[[Nitrogen cycle]]
[[Category:Bacteria]]
[[Category:Nitrogen metabolism]]
[[Category:Soil biology]]
[[Category:Microbiology]]
[[Category:Fishkeeping]]
[[Category:Aquaria]]