Methylococcaceae

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Methylococcaceae
Microscopic image of Methylococcus capsulatus

Microscopic image of Methylococcus capsulatus

Systematics
Domain : Bacteria (bacteria)
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Methylococcales
Family : Methylococcaceae
Scientific name
Methylococcaceae
Whittenbury & War 1984

Methylococcaceae form a family of the Proteobacteria and are, besides the Crenotrichaceae, the only member of the order Methylococcales . They belong to the methanotrophic bacteria, they are able to grow with methane as the only carbon source for the construction of the cell substance (assimilation) and for energy gain (through oxidation to methanol). By utilizing the greenhouse gas methane, they are ecologically very important.

The cells are rod-shaped or cocci-shaped . Cell chains sometimes appear. Some species form cyst-shaped bodies as resting stages.

metabolism

The Methylococcaceae belong to the methanotrophic bacteria, a subgroup of the methylotrophic bacteria. Methylotrophs are able to utilize compounds that have no C – C bonds. These molecules either contain only one carbon atom (e.g. methanol, methane) or no carbon atom is directly linked to another. The methanotrophic bacteria can usually only use methane and methanol . However, some strains are also able to use methylamine and a few other C1 compounds.

The methylotrophs, however, can also use some other compounds without direct CC bonds, such as B. trimethylamine , methylamine and dimethylamine . The methanotrophs also differ from the methylotrophs in that they possess the enzyme methane monooxygenase (MMO) and the ability to use CO 2 . With the help of the enzyme MMO, methane is oxidized to methanol and the energy gained is transferred to the respiratory chain and ATP is generated.

Bacteria of the genera Methylobacter , Methylococcus and Methylosphaera are also able to fix nitrogen.

Position within the methylotrophs

The methanotrophic bacteria are divided into three groups, groups I, II and X, based on different characteristics such as cell structure and metabolism. The Methylococcaceae form group I. They use monocarbon compounds in metabolism with the help of the ribulose monophosphate pathway . In the metabolism of group II, carbon is fixed via the serine pathway . Species of the Methylocystaceae family make up this group. Another distinguishing feature is the shape of the inner membranes. In group I they are arranged in stacks, in type II they run parallel to the outer cell membrane. Group X is in turn a subgroup of group I. The specialty of these bacteria is their ability to fix both methane and CO 2 . These include the genera Methylococcus and Methylocaldum .

Facultative methylotrophic bacteria are not dependent on monocarbon compounds, but can also use them, e.g. B. different types of Arthrobacter , Pseudomonas , Micrococcus and Bacillus .

Systematics

The bacterium Crenothrix polyspora , also known as fountain thread, is also able to oxidize methane. Analyzes of the 16S rRNA sequence show a close relationship with the species Methylobacter psychrophilus . According to NCBI, this species is in the family Crenotrichaceae, which belongs to the same order.

The Methylococcaceae currently consists of the following genera:

swell

  1. ^ A b Johannes CG Ottow : Microbiology of Soils: Biodiversity, Ecophysiology and Metagenomics , Springer Verlag, Heidelberg New York 2011, ISBN 3642008232 .
  2. ↑ a b Hanson RS, Hanson TE (1996) Methanotrophic bacteria. Microbiol Rev 60: 439-471
  3. ↑ Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (eds.) The Prokaryotes, A Handbook of the Biology of Bacteria. Volume 5: Proteobacteria: Alpha and Beta Subclasses, 3rd edition, Springer-Verlag, New York et al. O., 2006, ISBN 978-0-387-25495-1 (print) and ISBN 978-0-387-30743-5 (Online), doi: 10.1007 / 0-387-30743-5 .
  4. ↑ Stoecker, K. et al (2006): Cohn's Crenothrix is ​​a filamentous methane oxidizer with an unusual methane monooxygenase In: Proceedings of the National Academy of Sciences USA (PNAS) 103 (7), pp. 2363-2367; PMID 16452171 ; PMC 1413686 (free full text) (English)
  5. ↑ National Center for Biotechnology Information (NCBI)
  6. ↑ JP Euzéby: List of Prokaryotic Names with Standing in Nomenclature ( Memento of the original of January 12, 2008 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. As of November 2011 @1@ 2Template: Webachiv / IABot / www.bacterio.cict.fr

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: Bergey's manual of systematic bacteriology . 2nd Edition. Springer, New York, 2005, Volume 2: The Proteobacteria, Part B: The Gammaproteobacteria
  • Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer , Erko Stackebrandt (Eds.) The Prokaryotes, A Handbook of the Biology of Bacteria . 7 volumes, 3rd edition, Springer-Verlag, New York et al. O., 2006, ISBN 0-387-30740-0 . Vol. 2: Ecophysiology and Biochemistry ISBN 0-387-25492-7