Query: NC_009485:3461051 Bradyrhizobium sp. BTAi1 chromosome, complete genome
Lineage: Bradyrhizobium; Bradyrhizobium; Bradyrhizobiaceae; Rhizobiales; Proteobacteria; Bacteria
General Information: This organism is a photosynthetic rhizobium that is also capable of nitrogen-fixation, the first such example of such an organism. It can form nodules on the legume Aeschynomene indica and was isolated from this plant at the Boyce Thompson Institute for Plant Research in Ithaca, NY. It can form stem and root nodules. The photosynthetic reaction centers are similar to those found in purple photosynthetic bacteria and this microbe aids the plant in carbon metabolism and nitrogen metabolism.
Subject: NC_012560:3200961 Azotobacter vinelandii DJ, complete genome
Lineage: Azotobacter vinelandii; Azotobacter; Pseudomonadaceae; Pseudomonadales; Proteobacteria; Bacteria
General Information: This organism was first isolated from the soil in Vineland, New Jersey, although it is found worldwide. It is a large obligate aerobe that has one of the highest respiratory rates of any organism. Azotobacter vinelandii also produces a number of unusual nitrogenases which allow it to fix atmospheric nitrogen to ammonia, a compound it can then use as a nitrogen source. It protects the oxygen-sensitive nitrogenase enzymes through its high respiratory rate, which sequesters the nitrogenase complexes in an anoxic environment. This organism has a number of unusual characteristics. Under extreme environmental conditions, the cell will produce a cyst that is resistant to dessication and is surrounded by two capsular polysaccharide layers. This organism produces two industrially important polysaccharides, poly-beta-hydroxybutyrate (PHB) and alginate. PHB is a thermoplastic biopolymer, and alginate is used in the food industry. Alginate is also used by the pathogen Pseudomonas aeruginosa to infect the lungs of cystic fibrosis patients.