Nitrogen CompoundsNitrogenSarraceniaceaeNitratesQuaternary Ammonium CompoundsAmmoniaSoilNitritesCarbonRiversFresh WaterSoil MicrobiologyBacteriaEcosystemSeawaterCulture MediaNitrogen FixationPlantsNitrogen IsotopesNitrogen CycleBlood Urea NitrogenNitrogen DioxideReactive Nitrogen SpeciesNitrogen OxidesPII Nitrogen Regulatory ProteinsFertilizersGlutamate-Ammonia LigaseUreaNitrogen Mustard CompoundsNitrogenaseSymbiosisAmino AcidsBiomassPlant RootsGlutamineAcetylenePlant LeavesDigestionBacterial ProteinsAmmonium CompoundsGlutamate SynthaseGene Expression Regulation, BacterialAllantoinPhosphorusMolecular Sequence DataRoot Nodules, PlantNitrate ReductaseDenitrificationPoaceaePhotosynthesisCyanobacteriaAnimal FeedGenes, BacterialOxidation-ReductionMedicago sativa