Proteobacteria Guide, Meaning , Facts, Information and Description
Alpha Proteobacteria
Caulobacterales
Parvularculales
Rhizobiales - e.g. Rhizobium
Rhodobacterales
Rhodospirillales - e.g. Acetobacter
Rickettsiales - e.g. Rickettsia
Sphingomonadales
Beta Proteobacteria
Burkholderiales
Hydrogenophilales
Methylophilales
Neisseriales - e.g. Neisseria
Nitrosomonadales
Rhodocyclales
Procabacteriales
Gamma Proteobacteria
Acidithiobacillales
Aeromonadales - e.g. Aeromonas
Alteromonadales - e.g. Pseudoalteromonas
Cardiobacteriales
Chromatiales - purple sulfur bacteria
Enterobacteriales - e.g. Escherichia
Legionellales - e.g. Coxiella
Methylococcales
Oceanospirillales
Pasteurellales
Pseudomonadales - e.g. Pseudomonas
Thiotrichales - e.g. Thiomargarita
Vibrionales - e.g. Vibrio
Xanthomonadales - e.g. Stenotrophomonas
Delta Proteobacteria
Bdellovibrionales - e.g. Bdellovibrio
Desulfobacterales
Desulfovibrinoales
Desulfurellales
Desulfuromonadales
Myxococcales - myxobacteria
Syntrophobacterales
Epsilon Proteobacteria
Campylobacterales - e.g. Helicobacter
Nautiliales
The Proteobacteria are a major group of bacteria. They include a wide variety of pathogens, such as Escherichia, Salmonella, Vibrio, Helicobacter, and many other notable genera. Others are free-living, and include many of the bacteria responsible for nitrogen fixation. The group is defined mainly in terms of RNA sequences, and is named for the Greek god Proteus, who could change his shape, because of the great diversity of forms found in it.
All proteobacteria are Gram-negative, with a cell wall formed mainly of lipopolysaccharides. Many move about using flagella, but some rely on bacterial gliding. These include the myxobacteria, a unique group of bacteria that can aggregate to form multicellular fruiting bodies.
There is also a wide variety in the types of metabolism. Most proteobacteria are anaerobic, but there are many exceptions. The mitochondria that allow eukaryotic cells to conduct aerobic repiration are derived from proteobacteria, probably similar to rickettsias.
Nutrition is usually heterotrophic, but there are two groups that conduct photosynthesis, called purple bacteria. The purple sulfur bacteria use sulfur or hydrogen sulfide as an electron donor, and the purple non-sulfur bacteria use hydrogen. Because this role is not played by water, as it is among plants and cyanobacteria, no oxygen is produced.
The proteobacteria are divided into five sections, referred to by the Greek letters alpha through epsilon, again based on RNA sequences. Some may be paraphyletic. These are often treated as classes. The currently recognized orders are listed at right, together with some representative genera.
This is an Article on Proteobacteria. Page Contains Information, Facts Details or Explanation Guide About Proteobacteria