nitrogen fixation : Two kinds of nitrogen fixers are recognized: free-living (non-symbiotic) bacteria, including the cyanobacteria (or blue-green algae) Anabaena and Nostoc and such genera as Azotobacter, Beijerinckia, and Clostridium; and mutualistic (symbiotic) bacteria such as Rhizobium, associated with leguminous plants, and Spirillum lipoferum, associated with cereal grasses. dentrificatig bacteria : A group of bacteria that reduce nitrates or nitrites to nitrogen-containing gases. Potential examples include Thiobacillus denitrificans ,Micrococcus denitrificans & Paracoccus denitrificans .
involved in nitrification : There two bacterial species involved. Nitrosomonas sp. bacteria which oxidize ammonia to nitrite, while Nitrobacter bacteria convert nitrite to nitrate, with both species utilising the energy released by the reactions.
differece betwee nitrogen fixation & nitrification: Nitrification is the biological oxidation of ammonia with oxygen into nitrite followed by the oxidation of these nitrites into nitrates - carried out in soil by the action of nitrifying bacteria on decaying organic matter.
Nitrogen fixation is the conversion of atmospheric nitrogen into compounds, such as ammonia, by natural agencies or various industrial processes - eg. Rhizobium bacteria in the root nodules of legumes fix atmospheric nitrogen.
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