Dictionary > Nitrogen fixation

Nitrogen fixation

Definition
noun
The conversion of atmospheric nitrogen (N2) into a more usable form by natural means, such as by the conversion of nitrogen gas to ammonium (NH4+) by the action of diazotrophs
Supplement
Nitrogen in the atmosphere is one of the most abundant chemical elements and makes up a large part of the earth’s atmosphere. However, it is relatively inert, which means it does not readily react with other chemicals and produce compounds that are more readily available for use by plants, animals and other organisms. Only certain organisms are capable of a direct usage of nitrogen gas. Examples of these organisms are certain species of bacteria and archaea. They are referred to as diazotrophs. These bacteria are able to assimilate and then fix the nitrogen gas into a new nitrogen-containing compound (e.g. ammonia) that can be used more readily by other organisms such as plants. Rhizobia, Azospirillum, Klebsiella penumoniae, Clostridium and Azotobacter vinelandii are some of the microorganisms capable of nitrogen fixation. Rhizobium species are able to carry out nitrogen fixation only when they are in symbiotic association with leguminous plants. Rhizobium bacteria are found inside the root nodules of leguminous plants where they supply ammonia to the plant and the plant in turn provide for the organic acids (mainly dicarboxylic acids malate and succinate) as a carbon and energy source.
See also:


You will also like...

Freshwater aquatic plankton
Freshwater Communities & Plankton

Planktons are microscopic organisms that live suspended in aquatic habitats. There are two groups: the phytoplanktons an..

Cell Respiration
Cell Respiration

Cell respiration is the process of creating ATP. It is "respiration" because it utilizes oxygen. Know the different stag..

Nephrolepis exaltata
Vascular Plants: Ferns and Relatives

Ferns and their relatives are vascular plants, meaning they have xylem and phloem tissues. Because of the presence of va..

Chemical composition of the body
Chemical Composition of the Body

The body is comprised of different elements with hydrogen, oxygen, carbon, and nitrogen as the major four. This tutorial..

Plant biology
Plant Biology

Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

Salmon jumping upstream in the river
Lotic Communities & Animals

A running water environment offers numerous microhabitats for many types of animals. Similar to plants, animals in lotic..

Related Articles...

No related articles found

See all Related Topics