Azotobacter chroococcum

from Wikipedia, the free encyclopedia
Azotobacter chroococcum
Systematics
Department : Proteobacteria
Class : Gammaproteobacteria
Order : Pseudomonadales
Family : Pseudomonadaceae
Genre : Azotobacter
Type : Azotobacter chroococcum
Scientific name
Azotobacter chroococcum
Beijerinck 1901

Azotobacter chroococcum is a type of bacteria. This type may nitrogen in the presence of oxygen fix and is therefore of great ecological importance.

Appearance

The individuals of Azotobacter are mostly unicellular and relatively large, the diameter is 1.6-2.5 micrometers, the length 3-5 micrometers. Relatively young cells from a 24 hour old culture have rounded corners and are rod-shaped. In older cultures, cocci-shaped cells appear that often form pairs, sometimes groups of three or tetrads. Chains of cells can also appear. The cells can move with peritrich flagella (are motile). Older cultures are brown to black.

Nitrogen fixation

Azotobacter chroococcum has the ability under oxic conditions, i.e. H. to assimilate in the presence of oxygen , elemental, molecular nitrogen (N 2 ). The nitrogen is reduced to ammonia by the bacterium using a specific enzyme, a nitrogenase . This process is known as nitrogen fixation . In the following steps, ammonia is used for the formation of amino acids and thus for the construction of proteins as well as for the synthesis of other nitrogen-containing body building materials.

Systematics

Azotobacter chroococcum belongs to the family of Pseudomonadaceae , which is part of the Gammaproteobacteria . 7 species of the genus Azotobacter are known. Some authors consider Azotobacter and Azomonas to be members of the Azotobacteraceae family (also spelled with i: Azotobacteriaceae). Furthermore, the genera Azotobacter , Azorhizophilus and Azomonas are summarized by some authors in the Azotobacter group (Azotobacter group).

ecology

Azotobacter chroococcum is found in soils and running water.

Individual evidence

  1. ↑ Systematics according to JP Euzéby: List of Prokaryotic names with Standing in Nomenclature (LPSN) (as of September 14, 2017)
  2. ↑ JP Euzéby ( Memento of November 5, 2013 in the Internet Archive ): Azotobacteraceae
  3. ↑ NCBI

literature

  • George M. Garrity: Bergey's manual of systematic bacteriology . 2nd Edition. Springer, New York, 2005, Volume 2: The Proteobacteria, Part B: The Gammaproteobacteria , ISBN 0-387-24144-2
  • Jiri Hausler: Freshwater Flora of Central Europe, Vol. 20: Schizomycetes . Springer-Verlag, 1982. ISBN 978-3-8274-2141-8