Bradyrhizobiaceae
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| Scientific name | ||||||||||||
| Bradyrhizobiaceae | ||||||||||||
| ( Garrity et al., 2006) |
The Bradyrhizobiaceae are a family of bacteria . In terms of form, ecology and metabolism , this group includes very different species. With Nitrobacter and Bradyrhizobium , there are two types of bacteria that play an important role in the Earth's nitrogen cycle . The Bradyrhizobiaceae belong to the group of Proteobacteria . The Gram test falls, like all Proteobacteria, negative.
The prefix of the family name Brady- refers to the Greek adjective bradus for 'slow'. It has a slow growth speed of Bradyrhizobium out. The syllable rhizo means 'root' and refers to the symbiosis with plants ( nodule bacteria ).
Some genera
The genus Rhodoblastus contains phototrophic bacteria that carry out photosynthesis in the absence of oxygen to generate energy .
Types of bradyrhizobium belong to the nodule bacteria . These are nitrogen fixators that form symbioses, so-called root nodules, with various plants of the legume family . For example, Bradyrhizobium japonicum and Bradyrhizobium elkanii can enter into a symbiosis with the soybean . The bacterium makes nitrogen available to the plant, while the plant creates favorable living conditions for the bacterium. The plant brings nutrients to the bacterium and creates an environment in which the oxygen content is relatively low ( microaerophilic ), since nitrogen fixation can only take place under low- oxygen conditions. Bradyrhizobium is therefore very important agriculturally , as it makes nitrogen fertilizers unnecessary.
Agromonas can also fix nitrogen under microaerophilic conditions and was found in rice roots.
The genus Nitrobacter oxidizes nitrite to nitrate and thus plays an important role in the nitrogen cycle. The oxidation of nitrite to nitrate is a partial reaction of nitrification . Nitrification is part of the natural nitrogen cycle, whereby ammonia is oxidized to nitrate. Bacteria that are involved in this are called nitrifiers . The genus Nitrobacter is therefore of great ecological importance. In the first, preceding step of nitrification, other bacteria such as nitrosomonas oxidize ammonia to nitrite.
Afipia felis can cause symptoms of cat scratch disease .
But there are also free-living representatives such as the genus Rhodopseudomonas , which occurs in the sea and in soils.
Systematics
The following genera belong to the Bradyrhizobiaceae family:
- Afipia Brenner et al. 1992
- Agromonas Ohta and Hattori 1985
- Balneimonas corrig. Takeda et al. 2004
- Blastobacter Zavarzin 1961
- Bosea Das et al. 1996
- Bradyrhizobium Jordan 1982
- Nitrobacter Winogradsky 1892
- Oligotropha Meyer et al. 1994
- Rhodoblastus Imhoff 2001
- Rhodopseudomonas Czurda and Maresch 1937
- Salinarimonas Liu et al. 2010
Individual evidence
- ↑ Martin Dworkin, Stanley Falkow, Eugene Rosenberg, Karl-Heinz Schleifer, Erko Stackebrandt (Eds.): The Prokaryotes, A Handbook of the Biology of Bacteria . 3. Edition. Volume 2: Ecophysiology and Biochemistry . Springer, New York et al. O. 2006, ISBN 978-0-387-25492-0 , doi : 10.1007 / 0-387-30743-5 .
- ↑ Defeng Xing, Yi Zuo, Shaoan Cheng, John M. Regan, Bruce E. Logan: Electricity Generation by Rhodopseudomonas palustris DX-1 . In: Environmental Science & Technology . 42, No. 11, 2008, p. 4146. doi : 10.1021 / es800312v . PMID 18589979 .
- ↑ Bradyrhizobiaceae. In: LPSN List of Prokaryotic Names with Standing in Nomenclature. Retrieved February 21, 2014 .
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. Volume 2: The Proteobacteria Part C: The Alpha-, Beta-, Delta-, and Epsilonproteabacteria . Springer, New York 2005, ISBN 0-387-24145-0 .
