title: Growth of nitrite-oxidizing bacteria by aerobic hydrogen oxidation.
abstract: The bacterial oxidation of nitrite to nitrate is a key process of the biogeochemical nitrogen cycle. Nitrite-oxidizing bacteria are considered a highly specialized functional group, which depends on the supply of nitrite from other microorganisms and whose distribution strictly correlates with nitrification in the environment and in wastewater treatment plants. On the basis of genomics, physiological experiments, and single-cell analyses, we show that Nitrospira moscoviensis, which represents a widely distributed lineage of nitrite-oxidizing bacteria, has the genetic inventory to utilize hydrogen (H2) as an alternative energy source for aerobic respiration and grows on H2 without nitrite. CO2 fixation occurred with H2 as the sole electron donor. Our results demonstrate a chemolithoautotrophic lifestyle of nitrite-oxidizing bacteria outside the nitrogen cycle, suggesting greater ecological flexibility than previously assumed.
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
authors.forename: Hanna
authors.initials: H
authors.lastname: Koch
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Galushko
authors.affiliation: Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, 9000 Aalborg, Denmark.
authors.forename: Mads
authors.initials: M
authors.lastname: Albertsen
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria. Large Instrument Facility for Advanced Isotope Research, University of Vienna, 1090 Vienna, Austria.
authors.forename: Arno
authors.initials: A
authors.lastname: Schintlmeister
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
authors.forename: Christiane
authors.initials: C
authors.lastname: Gruber-Dorninger
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Lücker
authors.affiliation: Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de génomique, Genoscope, 91057 Evry, France. Centre National de la Recherche Scientifique, UMR8030, 91057 Evry, France. Université d'Evry Val d'Essonne, 91057 Evry, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Pelletier
authors.affiliation: Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, Institut de génomique, Genoscope, 91057 Evry, France. Centre National de la Recherche Scientifique, UMR8030, 91057 Evry, France. Université d'Evry Val d'Essonne, 91057 Evry, France.
authors.forename: Denis
authors.initials: D
authors.lastname: Le Paslier
authors.affiliation: Biozentrum Klein Flottbek, Microbiology and Biotechnology, University of Hamburg, 22609 Hamburg, Germany.
authors.forename: Eva
authors.initials: E
authors.lastname: Spieck
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Terrestrial Ecosystem Research, University of Vienna, 1090 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Richter
authors.affiliation: Center for Microbial Communities, Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, 9000 Aalborg, Denmark.
authors.forename: Per H
authors.initials: PH
authors.lastname: Nielsen
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Wagner
authors.affiliation: Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, 1090 Vienna, Austria. daims@microbial-ecology.net.
authors.forename: Holger
authors.initials: H
authors.lastname: Daims
mesh_terms: D000332:Aerobiosis; D001420:Bacteria, Aerobic / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D052837:Chemoautotrophic Growth / Q000235:genetics / Q000502:physiology*; D004734:Energy Metabolism; D056426:Genetic Loci; D006859:Hydrogen / Q000378:metabolism*; D006864:Hydrogenase / Q000235:genetics; D008969:Molecular Sequence Data; D009566:Nitrates / Q000378:metabolism; D058465:Nitrification / Q000235:genetics / Q000502:physiology; D009573:Nitrites / Q000378:metabolism*; D058458:Nitrogen Cycle; D010084:Oxidation-Reduction; D017422:Sequence Analysis, DNA
chemical_list: D009566:Nitrates; D009573:Nitrites; D006859:Hydrogen; D006864:Hydrogenase