Nitrosomonas

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Nitrosomonas
Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Betaproteobacteria
Order : Nitrosomonadales
Family : Nitrosomonadaceae
Genre : Nitrosomonas
Scientific name
Nitrosomonas
Winogradsky , 1892

Nitrosomonas is a genus of gram-negative bacteria from the Nitrosomonadaceae family .

features

The cells of Nitrosomonas are rod-shaped or spherical. Occasionally they are arranged in cell chains. The species are usually flagellated with flagella at the cell ends (polar). Some species form slimy cell aggregates under certain circumstances (e.g. Nitrosomonas oligotropha ). All types of nitrosomonas oxidize in the presence of oxygen, i.e. under oxic conditions, ammonium ions (NH 4 + ) and ammonia (NH 3 ) to nitrite ions (NO 2 - ), this genus is therefore one of the ammonia oxidizers. All generic names of ammonia oxidizing bacteria begin with “ nitroso- ”. Some species have the enzyme urease ; they can break down urea through hydrolysis .

ecology

The different species occur in different habitats. Some occur in soils ( Nitrosomonas communis , Nitrosomonas europaea , Nitrosomonas ureae ), some in bodies of water (e.g. Nitrosomonas eutropha ). Some species are salt-loving ( halophilic ) and can reproduce in high salt concentrations. So was z. B. Nitrosomonas halophila found in brackish water and in soda lakes . A cryophilic (cold-loving) species, Nitrosomonas cryotolerans , was found in the Gulf of Alaska and can be grown in the laboratory at temperatures as low as −5 ° C.

The nitrification

With their chemolithotrophic way of life, the species of Nitrosomonas are counted among the "nitrite bacteria". The oxidation of ammonium ions to nitrite ions is the first step in nitrification .

In the second step of nitrification, nitrate ions are oxidized to nitrate ions (NO 3 - ) in the natural environment by other bacteria such as nitrobacter , which are appropriately called “nitrate bacteria” . Representatives of both groups, "nitrite bacteria" and "nitrate bacteria", usually occur together, so that nitrite, which is toxic to many organisms, does not accumulate in their habitat. Nitrification is part of the natural nitrogen cycle .

Systematics

Nitrosomonas forms together with the genus Nitrosospira the family of Nitrosomonadaceae in the order of Nitrosomonadales . This order belongs to the class of the Betaproteobacteria . Nitrosomonas is the type genus of the family and the order. Nine species are currently included in the genus Nitrosomonas (as of 2014), N. europaea is the type species.

Synonyms for Nitrosomonas europaea are Planococcus europaeus , Bacterium nitrosomonas and Pseudomonas europaea . Nitrosomonas cryotolerans is not a valid published taxon . The species Nitrosomonas mobilis is to be regarded as not yet confirmed.

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literature

  • Michael T. Madigan, John M. Martinko, Jack Parker: Brock - Microbiology . 11th edition, Pearson Studium, Munich 2006, ISBN 3-8274-0566-1 .
  • George M. Garrity (Ed.): Bergey's Manual of Systematic Bacteriology . 2nd edition, Volume 2: The Proteobacteria. Part C: The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. Springer, New York 2005, ISBN 0-387-24145-0 .
  • S. Winogradsky: Contributions à la morphologie des organismes de la nitrification. In: Archives des Sciences Biologiques (St. Petersbourg) , Volume 1, 1892, pp. 86-137.

Individual evidence

  1. ↑ I. Suzuki, U. Dular, SC Kwok: Ammonia or Ammonium Ion as Substrate for Oxidation by Nitrosomonas europaea Cells and Extracts , J Bacteriol. 1974 October; 120 (1): 556-558. PMC 245802 (free full text)
  2. ^ A b Jean Euzéby, Aidan C. Parte: Genus Nitrosomonas. In: List of Prokaryotic names with Standing in Nomenclature ( LPSN ). Retrieved August 6, 2014 .
  3. ↑ Taxonomy Browser Nitrosomonas cryotolerans. In: National Center for Biotechnology Information (NCBI) website . Retrieved August 6, 2014 .

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