Many gram-negative bacteria produce and secrete siderophores under iron-deficient conditions. Siderophores are low molecular weight compounds (600-1500 Daltons), which chelate ferric iron with an extremely high affinity, and the complex is actively transported across the outer and inner membranes of gram-negative bacteria. There are two main classes of siderophores: catechol and hydroxamate. Catechol-type siderophores chelate ferric iron via hydroxyl groups, and hydroxamate-type siderophores chelate ferric iron via a carbonyl group with an adjacent nitrogen. Rhizobia fix atmospheric nitrogen symbiotically in leguminous plants using the iron-containing enzyme nitrogenase. To satisfy their iron requirements, many rhizobia are known to produce siderophores. Rhizobium leguminosarum Strain IARI 312 is known to infect pigeon pea plants. R. leguminosarum Strain IARI 312 produces both a catechol-type and a hydroxamate-type siderophore when grown under iron deficient conditions. The catechol-type siderophore has been purified and chemically characterized, and is consistent with that of enterobactin.
","abstract_html":"<p>Many gram-negative bacteria produce and secrete siderophores under iron-deficient conditions. Siderophores are low molecular weight compounds (600-1500 Daltons), which chelate ferric iron with an extremely high affinity, and the complex is actively transported across the outer and inner membranes of gram-negative bacteria. There are two main classes of siderophores: catechol and hydroxamate. Catechol-type siderophores chelate ferric iron via hydroxyl groups, and hydroxamate-type siderophores chelate ferric iron via a carbonyl group with an adjacent nitrogen. Rhizobia fix atmospheric nitrogen symbiotically in leguminous plants using the iron-containing enzyme nitrogenase. To satisfy their iron requirements, many rhizobia are known to produce siderophores. <em>Rhizobium leguminosarum</em> Strain IARI 312 is known to infect pigeon pea plants. <em>R. leguminosarum</em> Strain IARI 312 produces both a catechol-type and a hydroxamate-type siderophore when grown under iron deficient conditions. The catechol-type siderophore has been purified and chemically characterized, and is consistent with that of enterobactin.</p>","abstract_has_math":false,"creators":["Clark, Brianne Lee"],"institution":null,"degree_name":"MS (Master of Science)","degree_level":"Thesis - unrestricted","degree_discipline":"Biology","degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2004,"date_issued":"2004-08-18T07:00:00Z","date_published":"2004-08-18T07:00:00Z","updated_at":"2026-07-24T02:19:28Z","subjects":["Rhizobium leguminosarum","Siderophore","Iron Acquisition","Catechol","Enterobactin","Biology","Life Sciences"],"languages":[],"rights":["Copyright by the authors."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://dc.etsu.edu/etd/922","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Clark, Brianne Lee"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.issued","label":"Date","values":["2004-08-18T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biology"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - unrestricted"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS (Master of Science)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Rhizobium leguminosarum","Siderophore","Iron Acquisition","Catechol","Enterobactin","Biology","Life Sciences"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["Copyright by the authors."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://dc.etsu.edu/context/etd/article/2079/viewcontent/ClarkB080204f.pdf","https://dc.etsu.edu/etd/922"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Many gram-negative bacteria produce and secrete siderophores under iron-deficient conditions. Siderophores are low molecular weight compounds (600-1500 Daltons), which chelate ferric iron with an extremely high affinity, and the complex is actively transported across the outer and inner membranes of gram-negative bacteria. There are two main classes of siderophores: catechol and hydroxamate. Catechol-type siderophores chelate ferric iron via hydroxyl groups, and hydroxamate-type siderophores chelate ferric iron via a carbonyl group with an adjacent nitrogen. Rhizobia fix atmospheric nitrogen symbiotically in leguminous plants using the iron-containing enzyme nitrogenase. To satisfy their iron requirements, many rhizobia are known to produce siderophores. Rhizobium leguminosarum Strain IARI 312 is known to infect pigeon pea plants. R. leguminosarum Strain IARI 312 produces both a catechol-type and a hydroxamate-type siderophore when grown under iron deficient conditions. The catechol-type siderophore has been purified and chemically characterized, and is consistent with that of enterobactin.
"]},{"key":"dc:title","label":"Title","values":["Characterization of a Catechol-Type Siderophore and the Detection of a Possible Outer Membrane Receptor Protein from Rhizobium leguminosarum strain IARI 312."]}]}],"canonical_facts":{"dc:creator":["Clark, Brianne Lee"],"dc:date.issued":["2004-08-18T07:00:00Z"],"dc:description.abstract":["Many gram-negative bacteria produce and secrete siderophores under iron-deficient conditions. Siderophores are low molecular weight compounds (600-1500 Daltons), which chelate ferric iron with an extremely high affinity, and the complex is actively transported across the outer and inner membranes of gram-negative bacteria. There are two main classes of siderophores: catechol and hydroxamate. Catechol-type siderophores chelate ferric iron via hydroxyl groups, and hydroxamate-type siderophores chelate ferric iron via a carbonyl group with an adjacent nitrogen. Rhizobia fix atmospheric nitrogen symbiotically in leguminous plants using the iron-containing enzyme nitrogenase. To satisfy their iron requirements, many rhizobia are known to produce siderophores. Rhizobium leguminosarum Strain IARI 312 is known to infect pigeon pea plants. R. leguminosarum Strain IARI 312 produces both a catechol-type and a hydroxamate-type siderophore when grown under iron deficient conditions. The catechol-type siderophore has been purified and chemically characterized, and is consistent with that of enterobactin.
"],"dc:identifier":["https://dc.etsu.edu/context/etd/article/2079/viewcontent/ClarkB080204f.pdf","https://dc.etsu.edu/etd/922"],"dc:rights":["Copyright by the authors."],"dc:subject":["Rhizobium leguminosarum","Siderophore","Iron Acquisition","Catechol","Enterobactin","Biology","Life Sciences"],"dc:title":["Characterization of a Catechol-Type Siderophore and the Detection of a Possible Outer Membrane Receptor Protein from Rhizobium leguminosarum strain IARI 312."],"thesis:degree_discipline":["Biology"],"thesis:degree_level":["Thesis - unrestricted"],"thesis:degree_name":["MS (Master of Science)"]},"updated_at":"2026-07-24T02:19:28Z"}