What are two functions of bacteria in the nitrogen cycle?

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marilynn07 eNotes educator| Certified Educator

Bacteria break the bonds in hydrogen gas molecules and allow the free nitrogen to bond with hydrogen to form ammonium. Ammonium is an ion that is readily absorbed by plants. These are nitrogen-fixing bacteria. There are some that have formed a symbiotic relationship with legumes.

Bacteria release nitrogen bound up in formerly living things through the process of ammonification or decomposition. These bacteria convert the nitrogen from dead organisms into ammonium ions.

Bacteria provide plants with a usable form of nitrogen that they would be unable to get if all the available nitrogen were in the form of a gas.


sid-sarfraz | Student

Lighting , artificial fertilizers and nitrogen-fixing bacteria in the soil and in root nodules convert nitrogen into nitrates.

The two functions of bacteria in the nitrogen cycle are as follows:-

  1. Nitrifying bacteria in the soil changes animal waste and dead remains of animals into ammonia and eventually nitrates.
  2. Denitrifying bacteria live in water-logged soils and convert nitrates back into nitrogen.
bejaranito | Student

If bacteria loss ability to fix nitrogen what happen in economy and environment

helen75 | Student


The ability to fix nitrogen is only with certain bacteria . The proteins made by plants enter and pass through food webs just as carbohydrates do. The bacteria break down the molecules in excretions and dead organisms into ammonia. Ammonia can be taken up directly by plants — usually through their roots. However, most of the ammonia produced by decay is converted into nitrates.