MolybdenumPteridinesCoenzymesMetalloproteinsTungstenNitrogen FixationNitrate ReductasesXanthine DehydrogenaseNitrate ReductaseAldehyde OxidaseSulfite OxidaseSulfurtransferasesPterinsXanthine OxidaseNitrogenaseTungsten CompoundsOxidoreductases Acting on Sulfur Group DonorsNitrogen IsotopesSulfurNitrogen CompoundsNitrate Reductase (NADH)Nitrogen CycleBlood Urea NitrogenNitrogen DioxideAldehyde OxidoreductasesMolybdoferredoxinElectron Spin Resonance SpectroscopyRhodobacter capsulatusOxidoreductasesIsotopesReactive Nitrogen SpeciesNitratesMetal Metabolism, Inborn ErrorsFormate DehydrogenasesOxidation-ReductionIron-Sulfur ProteinsAzotobacter vinelandiiChloratesAzotobacterXanthineNitrogen OxidesAmmoniaPII Nitrogen Regulatory ProteinsCarbonSulfite DehydrogenaseBacterial ProteinsDesulfovibrio gigasEscherichia coliOrganometallic CompoundsMolecular Sequence DataDithioniteFertilizersSpectrophotometrySoilMetalloexopeptidasesTracheobiontaSulfitesMilkChlorellaKineticsNitrobacterTrace ElementsQuaternary Ammonium CompoundsSulfidesFormatesCatalysisIronGene Expression Regulation, BacterialGlutamate-Ammonia LigaseGenes, BacterialHydrogen-Ion ConcentrationAmino Acid SequenceMetalsMutationAmino AcidsAnaerobiosisMethanobacteriumAcetyleneHumic SubstancesOxygen IsotopesFerredoxinsCopperUrea