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.

You might interest more articles about Soil Science

Useful Agricultural Websites

Online Agricultural Study

Food and Agricultural Organization

United States Department of Agriculture

Leave a Comment