Asymbiotic Nitogen Fixation

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Asymbiotic organism are those that live independently and carry on their life processes without the help of other organism .Some of the soil bacteria that are capable of utilizing atmospheric nitrogan.Eg Achromobacter,Aerobacter,Azotobacter,Beijerinckia,Clostridium,Granulobacter,Pseudomonas and Radiobacter.Among them Azotobacter,Clostridium and Beijerinckia are more important organism as they fix more amount of Nitrogen.The estimated amount of N2 fixation was 700mg/m^2/y^2.But symbiotic association fix 500kg of nitrogen.
       The non symbiotic organism are divided into 2 .They are Anareobic and aerobic.
Anaerobic bacteria :
            Clostridium is the most important bacteria in anaerobic section which is first isolated by Winogradsky in 1891 and named as Clostridium pasterurianum.It is spore forming bacteria  .About dozen species of Clostridium are isolated and it is more abundant than Azotobacter but fix less nitrogen.
Aerobic:
         Azotobacter is the important organism in this section which is discovered by Beijerinck in 1901 named as Azotobacter chrococcum.
         The chemical process by which an inert gas like nitrogen is utilize and fixed by these organism are not yet definitely known .As stated earlier the gaseous N2 is ultimately converted into complex protein of bacteral protoplasm.The organism contain of system of enzymes one of which ,nitrogenaseand combined with and activated as the gas.The gaseous N2 is is first oxidized to nitrous oxide which with water give rise to hyponitrous acid .Then this acid is reduce to ammonia with the possible formation of hydroxylamine as an independent product.The amonia then combined with some of the decomposition product of carbohydrate especially the organic acid such as glutaric acid to from ammino acid.eg glutamic acid

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