What is the role of nitrogen-fixing bacteria in the nitrogen cycle?
Nitrogen-fixing bacteria:
1. Nitrogen-fixing bacteria convert free nitrogen gas into nitrogen compounds.
2. Nitrogen fixation, is any natural or industrial process that causes free nitrogen (N2).
3. Nitrogen cannot be used by most organisms unless it is combined with or “fixed” with other elements to form nitrogenous compounds.
4. Nitrogen fixation occurs in nature either due to lightning or nitrogen-fixing bacteria.
5. There are two broad groups of nitrogen-fixing bacteria.
(i) The first group includes the free-living bacteria that are not attached to any plant in particular and are found in the soil or water. Examples of this group include the genera Clostridium and Azotobacter, as well as some blue-green algae.
(ii) The second group includes bacteria that live on the roots of certain legumes. This consists of bacteria from the Rhizobium genus, which live in nodules found on the root of the plants.