CarbonNitrogen FixationCarbon DioxideCarbon MonoxideNanotubes, CarbonNitrogen IsotopesNitrogen CompoundsNitrogen CycleNitrogen DioxideBlood Urea NitrogenCarbon Monoxide PoisoningCarbon IsotopesReactive Nitrogen SpeciesNitrogen OxidesPII Nitrogen Regulatory ProteinsCarbon TetrachlorideCarbon SequestrationNitratesAmmoniaCarbon DisulfideBiomassFertilizersSoilQuaternary Ammonium CompoundsCarbon Tetrachloride PoisoningGlutamate-Ammonia LigaseCulture MediaAmino AcidsUreaSymbiosisAtmospherePhotosynthesisPlant LeavesNitrogenaseMolecular Sequence DataNitrogen Mustard CompoundsBacterial ProteinsEcosystemOxidation-ReductionCarbon FootprintGene Expression Regulation, BacterialPlant RootsCarbon RadioisotopesBiodegradation, EnvironmentalTreesGlutamineOxygenAcetyleneSoil MicrobiologyCarbohydrate MetabolismBacteriaFermentationHydrogen-Ion ConcentrationNitrogenGlucoseSootGenes, BacterialPhosphorusSeawaterPoaceaeTemperatureAir PollutantsMethaneCarboxyhemoglobinAcetatesKineticsGlutamate SynthaseMutationNitritesAnaerobiosisGasesDigestionGene Expression Regulation, FungalCyanobacteriaSulfurAmmonium CompoundsKetoglutaric AcidsDenitrificationRoot Nodules, PlantNitrate ReductaseAllantoinEnvironmental MonitoringTime FactorsWaterAerobiosisModels, BiologicalAutotrophic ProcessesPhylogenyPlantsMagnetic Resonance SpectroscopyEscherichia coliGeologic SedimentsMetabolic Networks and PathwaysGraphiteCarbon Compounds, InorganicAgricultureBase SequenceOxidoreductasesPseudomonasSaccharomyces cerevisiae