What is the Difference Between Bradyrhizobium and Rhizobium?

Bradyrhizobium and Rhizobium are both nitrogen-fixing soil bacteria that form symbiotic relationships with leguminous plants. However, there are some differences between the two genera:

1. Growth rate: Bradyrhizobium species are slow-growing, while Rhizobium species are fast-growing.
2. Cell shape and flagella: Bradyrhizobium species are rod-shaped bacteria with a single subpolar or polar flagellum, while Rhizobium species are also rod-shaped but have a single polar or 2-6 peritrichous flagella.
3. Family: Bradyrhizobium belongs to the family Bradyrhizobiaceae, which has 10 genera, while Rhizobium belongs to the family Rhizobiaceae.
4. Carbon source utilization: Some Bradyrhizobium species tend to grow best with pentoses as carbon sources, while Rhizobium species may have different carbon source preferences.
5. Habitat: Rhizobium mainly lives within nodules of legumes in wetter regions, while Bradyrhizobium lives with legumes in drier regions.

Despite these differences, both Bradyrhizobium and Rhizobium play essential roles in nitrogen fixation and are beneficial to the environment and agriculture.

Comparative Table: Bradyrhizobium vs Rhizobium

Here is a table comparing the differences between Bradyrhizobium and Rhizobium:

Both Bradyrhizobium and Rhizobium are gram-negative, rod-shaped bacteria that fix atmospheric N2 and belong to the phylum proteobacteria. They are both motile bacteria with circular chromosomes.