Rhizobium
| Rhizobium | |
|---|---|
 |
|
| Rhizobium tropici on an agar plate. | |
| Scientific classification | |
| Kingdom: | Bacteria |
| Phylum: | Proteobacteria |
| Class: | Alphaproteobacteria |
| Order: | Rhizobiales |
| Family: | Rhizobiaceae |
| Genus: |
Rhizobium Frank 1889 |
| Type species | |
|
Rhizobium leguminosarum |
|
| Species | |
Rhizobium is a genus of Gram-negative soil bacteria that fix nitrogen. Rhizobium species form an endosymbiotic nitrogen-fixing association with roots of legumes and .
The bacteria colonize plant cells within root nodules, where they convert atmospheric nitrogen into ammonia and then provide organic nitrogenous compounds such as glutamine or ureides to the plant. The plant, in turn, provides the bacteria with organic compounds made by photosynthesis. This mutually beneficial relationship is true of all of the rhizobia, of which the Rhizobium genus is a typical example.
Beijerinck in the Netherlands was the first to isolate and cultivate a microorganism from the nodules of legumes in 1888. He named it Bacillus radicicola, which is now placed in Bergey's Manual of Determinative Bacteriology under the genus Rhizobium.
Rhizobium forms a symbiotic relationship with certain plants such as legumes, fixing nitrogen from the air into ammonia, which acts as a natural fertilizer for the plants. Current research is being conducted by Agricultural Research Service microbiologists to discover a way to use Rhizobium’s biological nitrogen fixation. This research involves the genetic mapping of various rhizobial species with their respective symbiotic plant species, like alfalfa or soybean. The goal of this research is to increase the plants’ productivity without using fertilizers. [1]
...
Wikipedia