Bradyrhizobiaceae

The Bradyrhizobiaceae are a family of bacteria. Are in this group in terms of form, ecology and metabolism, summarized very different ways. With Nitrobacter and Bradyrhizobium here are two genera of bacteria present, which play an important role in the nitrogen cycle of the earth. 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 points to the slow growth speed of Bradyrhizobium. The syllable means rhizosphere, root ' and refers to the symbiosis with plants ( rhizobia ).

Some genres

The genus contains Rhodoblastus phototrophic bacteria that carry out photosynthesis in the absence of oxygen to produce energy.

Types of Bradyrhizobium are among the root nodule bacteria. These are nitrogen fixers with various plants of the legume family ( Leguminosae ) symbioses, which are called root nodules. For example, Bradyrhizobium japonicum and Bradyrhizobium received elkanii with the soybean symbiosis. Herein, the bacterium nitrogen of the plant is available, while the plant the bacterium creates favorable living conditions. The plant brings the bacterium nutrients and creates an environment in which the oxygen content is relatively low ( microaerophilic ) because the nitrogen fixation can take place only under oxygen- poor conditions. Agricultural Bradyrhizobium is thus very important because it makes the nitrogen fertilizers unnecessary.

Agro Monas 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, in which ammonia is oxidized to nitrate. Bacteria which are involved in this case is referred to as nitrifying bacteria. The genus Nitrobacter thus has a great ecological importance. In the first, preliminary step of nitrification are oxidized to nitrite by other bacteria such as Nitrosomonas ammonia.

Afipia felis can cause symptoms of cat scratch disease.

There are also free-living representatives such as the genus Rhodopseudomonas, which is found in the ocean and in soils.

System

To the family Bradyrhizobiaceae include the following genera:

• Afipia Brenner et al. 1992
• Agro Monas 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