What is Bradyrhizobium?
{{Orphan|date=July 2023}} '''''Bradyrhizobium''''' is a genus of [[Gram-negative]] soil [[bacteria]] that naturally occur as free-living soil bacteria or in [[Symbiosis|symbiotic relationships]] with legumes. ''Bradyrhizobium'' is known for [[nitrogen fixation]], which converts atmospheric nitrogen into ammonia (N<sub>2</sub> - NH<sub>3</sub>). This process allows [[plant]]s and other organisms to use [[organic compound]]s, such as [[nitrate]]s, more readily.<ref>Wagner, S. C.. (2011) Biological Nitrogen Fixation. ''Nature Education Knowledge'' 3(10):15</ref><ref>Wongdee, J., Boonkerd, N., Teaumroong, N., Tittabutr, P., & Giraud, E. (2018). Regulation of Nitrogen Fixation in ''Bradyrhizobium'' sp. Strain DOA9 Involves Two Distinct NifA Regulatory Proteins That Are Functionally Redundant During Symbiosis but Not During Free-Living Growth. ''Frontiers in microbiology'', ''9'', 1644. <nowiki>https://doi.org/10.3389/fmicb.2018.01644</nowiki></ref> Nitrogen-fixing bacteria such as ''Bradyrhizobium'' are crucial to chemical cycles in the soil. == Microbiology == === Ecology === ''Bradyrhizobium'' species are Gram-negative, rod-shaped (also called bacilli) with a [[Flagellum|flagella]] (like a tail) to help them move through their environment. Gram-negative bacteria are smaller types of bacteria with thin cell walls that are sensitive to drought or water stress.<ref>{{Cite web|last=Hoorman|first=James J.|date=June 6, 2016|title=Role of Soil Bacteria|url=https://ohioline.osu.edu/factsheet/anr-36|access-date=July 2, 2023|website=The Ohio State University: College of Food, Agriculture, and Environmental Sciences}}</ref> They are commonly found in the soil where they can form relationships with plant roots such as [[pea]]s, [[clover]], and other [[legume]]s in a mutually beneficial, or [[Symbiosis|symbiotic]], relationship. In exchange for their nitrogen fixation, the ''Bradyrhizobium'' benefit from [[carbohydrate]]s made by the plant. They are also common in forest soils, although these species tend not to fix nitrogen.