All organisms require nitrogen for the formation of the DNA molecule, amino acids, and proteins. Atmospheric nitrogen is not a readily usable substance for autotrophs or heterotrophs.
The nitrogen molecule must be broken apart and converted into biologically useful forms, such as ammonia, the ammonium ion, nitrites, and nitrates. This typically happens in the soil so that these forms of nitrogen can be uptaken by plants and incorporated into their tissues.
What is the name of the process by which nitrates lost their oxygen atoms and are converted back into atmospheric nitrogen?