Nif gene are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms and are found in both free-living nitrogen-fixing bacteria and in symbiotic bacteria, also referred as diazotroph, associated with various plants.
The nif genes are genes encoding enzymes involved in the fixation of atmospheric nitrogen into a form of nitrogen available to living organisms. The nif genes are found in both free-living nitrogen-fixing bacteria and in symbiotic bacteria associated with various plants. Diazotrophs are bacteria and archaea that fix atmospheric nitrogen gas into a more usable form such as ammonia. 
