title: Effect of organic matter on nitrogenase metal cofactors homeostasis in Azotobacter vinelandii under diazotrophic conditions.
abstract: Biological nitrogen fixation can be catalysed by three isozymes of nitrogenase: molybdenum (Mo)-nitrogenase, vanadium (V)-nitrogenase and iron-only (Fe)-nitrogenase. The activity of these isozymes strongly depends on their metal cofactors, molybdenum, vanadium and iron, and their bioavailability in ecosystems. Here, we show how metal bioavailability can be affected by the presence of tannic acid (organic matter), and the subsequent consequences on diazotrophic growth of the soil bacterium Azotobacter vinelandii. In the presence of tannic acids, A. vinelandii produces a higher amount of metallophores, which coincides with an active, regulated and concomitant acquisition of molybdenum and vanadium under cellular conditions that are usually considered not molybdenum limiting. The associated nitrogenase genes exhibit decreased nifD expression and increased vnfD expression. Thus, in limiting bioavailable metal conditions, A. vinelandii takes advantage of its nitrogenase diversity to ensure optimal diazotrophic growth.
authors.affiliation: Département de Chimie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.|Laboratory of Bacterial Molecular Genetics, Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.
authors.forename: Christelle Jouogo
authors.initials: CJ
authors.lastname: Noumsi
authors.affiliation: Département de Chimie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.
authors.forename: Nina
authors.initials: N
authors.lastname: Pourhassan
authors.affiliation: Département de Chimie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.
authors.forename: Romain
authors.initials: R
authors.lastname: Darnajoux
authors.affiliation: Institute for Inorganic and Analytical Chemistry, Jena School for Microbial Communication, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Deicke
authors.affiliation: Institute for Inorganic and Analytical Chemistry, Jena School for Microbial Communication, Friedrich Schiller University Jena, Jena, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Wichard
authors.affiliation: Laboratory of Bacterial Molecular Genetics, Département de biologie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Burrus
authors.affiliation: Département de Chimie, Faculté des sciences, Université de Sherbrooke, 2500 boul. de l'université, Sherbrooke, Québec, J1K 2R1, Canada.
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Bellenger
mesh_terms: D016948:Azotobacter vinelandii / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism*; D003067:Coenzymes / Q000378:metabolism; D006706:Homeostasis; D008670:Metals / Q000378:metabolism*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000378:metabolism*; D013634:Tannins / Q000378:metabolism*
chemical_list: D003067:Coenzymes; D008670:Metals; D013634:Tannins; D009591:Nitrogenase