Nitrogen FixationAzospirillumAcetyleneNitrogenaseInorganic ChemicalsProteobacteriaGram-Negative Facultatively Anaerobic RodsCyanobacteriaSeawaterPacific OceanSoil MicrobiologyPseudomonas stutzeriPoaceaeGammaproteobacteriaOxidoreductasesPhylogenyBacteriaDNA, RibosomalRNA, Ribosomal, 16SPlant RootsSequence Analysis, DNADNA, BacterialMolecular Sequence DataPolymerase Chain Reaction