The Rhizobiaceae Project
Rhizobia are bacteria that form a symbiotic relationship with legumes such as alfalfa, clover, peas, and beans. The bacteria fix atmospheric nitrogen and supply the nitrogen to the legumes and the plant provides carbohydrates to the bacteria. Since the bacteria and their phages are found in almost all soil types, they are an excellent source of genetic biodiversity data. Also, since rhizobia are frequently used to inoculate legume seed, phages can be used to allow the best nitrogen-fixing bacteria to infect the roots of legumes.