Nitrogen FixationNitrogen IsotopesPhylogenyNitrogen CompoundsNitrogen CycleBlood Urea NitrogenNitrogen DioxideRNA, Ribosomal, 16SDNA, RibosomalReactive Nitrogen SpeciesMolecular Sequence DataSequence Analysis, DNADNA, BacterialNitrogen OxidesPII Nitrogen Regulatory ProteinsGenes, rRNABase CompositionSpecies SpecificityNitratesAmmoniaCarbonFertilizersBacterial Typing TechniquesQuaternary Ammonium CompoundsActinomycetalesFatty AcidsSeawaterGlutamate-Ammonia LigaseSoilRNA, BacterialUreaNitrogen Mustard CompoundsBase SequenceBacteriaNitrogenaseAmino AcidsGeologic SedimentsPlant RootsBacterial ProteinsBiomassSymbiosisPlant LeavesDNA, Ribosomal SpacerEcosystemNucleic Acid HybridizationCulture MediaWater MicrobiologyFresh WaterAlphaproteobacteriaGenes, BacterialPhenotypeAerobiosisGlutaminePoaceaeAcetyleneTreesCluster AnalysisGene Expression Regulation, BacterialSequence Homology, Nucleic AcidCyanobacteriaDigestionQuinonesNitritesGammaproteobacteriaRoot Nodules, PlantAnaerobiosisOxidation-ReductionPhotosynthesisHydrogen-Ion ConcentrationPhosphorusPigments, BiologicalSodium ChlorideTemperatureAmmonium CompoundsGlutamate SynthaseAllantoinEvolution, MolecularAmino Acid SequenceDenitrificationFabaceaeVitamin K 2RhizobiumSulfurBiodiversityBiodegradation, EnvironmentalPlantsKoreaNitrate ReductaseTerminology as TopicCarbohydrate MetabolismFungiBiological EvolutionAscomycotaDNA, FungalBacteroidetesAnimal FeedSewageMedicago sativaFecesRhizobiaceae