Isolation and Identification of the Siderophore "Vicibactin" Produced by <em>Rhizobium leguminosarum</em> ATCC 14479.

• Main Author: Wright, William H., IV
• Format: Others
• Published: Digital Commons @ East Tennessee State University 2010
• Subjects: siderophore; vicibactin; Rhizobium leguminosarum ATCC 14479; Bacteriology; Life Sciences; Microbiology
• Online Access: https://dc.etsu.edu/etd/1690; https://dc.etsu.edu/cgi/viewcontent.cgi?article=3045&amp;context=etd

Siderophores are small, iron chelating molecules produced by many bacteria to help meet the iron requirements of the cell. Multiple metabolic functions require iron as it serves as a cofactor in many enzymes and cellular processes. However, in the presence of oxygen and at physiologic pH, iron forms insoluble ferric complexes that cause the nutrient to be unavailable to bacterial cells. Siderophores alleviate this limitation by chelating the ferric iron, rendering it soluble and available for uptake. One group of microorganisms known for their ability to produce siderophores is the rhizobia. These bacteria are characterized both by their formation of symbiotic relationships with leguminous plants and their ability to fix atmospheric nitrogen. Rhizobium leguminosarum ATCC 14479, which infects the red clover Trifolium pratense, was found to produce a trihydroxamate siderophore. Purification and chemical characterization identified this siderophore as Vicibactin that has been found to be produced by other rhizobial strains.