Concept of Biological Nitrogen Fixation (BNF) and its Reaction, and Classification
Concept of Biological Nitrogen Fixation (BNF)
Biochemical reduction of atmospheric inert N2 by certain microorganism with the help of a special kind of enzyme (Nitrogenase). They contain to organic combination or to the form readily usable biological process is called Biological Nitrogen Fixation
OR, the process of converting inert dry nitrogen into organic combination or in to other utilizable form Biochemically is known as BNF.
It is an important Biochemical reaction for life to the earth. Through these process certain organism converts inert dinitrogen gas of the atmosphere to nitrogen containing organic compound that become available to all forms of life through Nitrogen Cycle.
Regardless of the organism involves, the key to Biological Nitrogen Fixation is the enzyme “Nitrogenase” which catalyze the reduction of dinitrogen gas to Ammonia.
Reaction of Biological Nitrogen Fixation (BNF)
It is completed in 2 steps
1. Atmospheric N2 reduce to NH3 through the enzyme Nitrogenase.
N2 + 6H+ +6e → 2NH3
2. NH3 thus produced in synthesized to a stable compound protein.
NH3 + organic acid → Protein.
Classification of Biological Nitrogen Fixation (BNF)
BNF are mainly 2 types
1. Symbiotic Nitrogen Fixation. 2. Nonsymbiotic Nitrogen Fixation
1. Symbiotic Nitrogen Fixation
The Biochemical reduction of atmospheric inert dry nitrogen carried out by an association of two dissimilar organism living intimately to the soil and water in which both of the partners are benefited. If may be following 2 types
§ Leguminous Symbiosis e.g. legumerhizobium symbiosis.
§ Nonleguminous symbiosis e.g. AzollaAnabaena symbiosis.
2. Nonsymbiotic Nitrogen Fixation
The Biochemical reduction of atmospheric inert dry nitrogen carried out by an an individual organism living freely soil and water. e.g Azotobacter (aerobic), Clostridium (anaerobic), BGA etc.