Nitrogen Cycle

• Ammonification:

  Nitrogen gas containing molecules are converted to Ammonium ions by saprobiotic bacteria and fungi.
• Nitrification:

  Oxidation of ammonium ions into nitrite ions and then oxidised into nitrate ions by aerobic nitrifying bacteria.
• Nitrogen Fixation:

  Conversion of nitrogen gas into ammonium ions by nitrogen fixing bacteria.
• Nitrogen Fixing Bacteria are found free in the soil and bacteria in root nodules of legume plants. The plants produce nitrogen containing biological molecules using these ammonium ions. The plants and bacteria have a mutualistic relationship.
• Denitrification:

  Conversion of nitrate ions back to nitrogen gas by anaerobic denitrifying bacteria.