Pseudomonadota is a major phylum of Gram-negative bacteria. The renaming of several prokaryote phyla in 2021, including Pseudomonadota, remains controversial among microbiologists, many of whom continue to use the earlier name Proteobacteria, of long standing in the literature. The phylum Proteobacteria includes a wide variety of pathogenic genera, such as Escherichia, Salmonella, Vibrio, Yersinia, Legionella, and many others. Others are free-living (non-parasitic) and include many of the bacteria responsible for nitrogen fixation.
The Rhodospirillales are an order of Pseudomonadota.
The Campylobacterales are an order of Campylobacterota which make up the epsilon subdivision, together with the small family Nautiliaceae. They are Gram-negative. Most of the species are microaerophilic.
The Burkholderiales are an order of Pseudomonadota. Like all Pseudomonadota, they are Gram-negative. They include several pathogenic bacteria, including species of Burkholderia, Bordetella, and Ralstonia. They also include Oxalobacter and related genera, which are unusual in using oxalic acid as their source of carbon. Other well-studied genera include Alcaligenes, Cupriavidus, Achromobacter, Comamonas, Delftia, Massilia, Duganella, Janthinobacterium, Polynucleobacter, non-pathogenic Paraburkholderia, Caballeronia, Polaromonas, Thiomonas, Collimonas, Hydrogenophaga, Sphaerotilus, Variovorax, Acidovorax, Rubrivivax and Rhodoferax, and Herbaspirillum.
The Rhodocyclaceae are a family of gram-negative bacteria. They are given their own order in the beta subgroup of Pseudomonadota, and include many genera previously assigned to the family Pseudomonadaceae.
The Hyphomicrobiales are an order of Gram-negative Alphaproteobacteria.
Purple bacteria or purple photosynthetic bacteria are Gram-negative proteobacteria that are phototrophic, capable of producing their own food via photosynthesis. They are pigmented with bacteriochlorophyll a or b, together with various carotenoids, which give them colours ranging between purple, red, brown, and orange. They may be divided into two groups – purple sulfur bacteria and purple non-sulfur bacteria. Purple bacteria are anoxygenic phototrophs widely spread in nature, but especially in aquatic environments, where there are anoxic conditions that favor the synthesis of their pigments.
The Desulfuromonadales are an order within the Thermodesulfobacteriota. Various members of the Desulfomonadales are capable of anaerobic respiration utilizing a variety of compounds as electron acceptors, including sulfur, Mn(IV), Fe(III), nitrate, Co(III), Tc(VII), U(VI) and trichloroacetic acid
The Alcaligenaceae are a family of bacteria, included in the order Burkholderiales. Members are found in water, soil, humans, and other animals. Some species, like Bordetella, are pathogenic for humans and for some other animals.
The Oxalobacteraceae are a family of bacteria, included in the order Burkholderiales. Like all Pseudomonadota, Oxalobacteraceae are Gram-negative. The family includes strict aerobes, strict anaerobes, and nitrogen-fixing (diazotrophic) members. The cells are curved, vibroid, or straight rod-shaped.
The Piscirickettsiaceae are a family of Pseudomonadota. All species are aerobes found in water. The species Piscirickettsia salmonis is a fish pathogen and causes piscirickettsiosis in salmonid fishes. It lives in cells of infected hosts and cannot be cultured on artificial media. Piscirickettsia salmonis is nonmotile, whereas the other five genera are motile by using a single flagellum.
Betaproteobacteria are a class of Gram-negative bacteria, and one of the eight classes of the phylum Pseudomonadota.
Spirillum is a genus of Gram-negative bacteria in the family Spirillaceae of the Nitrosomonadales of the Betaproteobacteria. There are two species of Spirillum with validly or effectively published names - Spirillum winogradskyi and Spirillum volutans.
Achromobacter is a genus of bacteria, included in the family Alcaligenaceae in the order Burkholderiales. The cells are Gram-negative straight rods and are motile by using one to 20 peritrichous flagella. They are strictly aerobic and are found in water and soils. They have also been identified as a contaminant in laboratory cell cultures. They have been identified as opportunistic human pathogens in people with certain immunosuppressive conditions such as cystic fibrosis, cancer and kidney failure.
In taxonomy, Rhodothalassium is a genus of the Rhodobacteraceae. Up to now there is only one species of this genus known.
Oxalobacter is a genus of bacteria in the Oxalobacteraceae family. The species are chemoorganotrophs and strictly anaerobic. They are found in rumens of animals such as cattle and in feces of other animals and humans. Some are marine and some have been isolated from fresh water. These bacteria are characterized by their ability to metabolize oxalate.
Pelobacter is a bacterial genus in the order Desulfuromonadales. The cells are rod-shaped with rounded ends and occur in single, pairs or chains. They have a fermentative metabolism.
Seliberia is a genus of rod-shaped bacteria.
Asaia is a genus of Gram-negative, aerobic and rod-shaped bacteria from the family of Acetobacteraceae which occur in tropical plants. Asaia might be able to control malaria by massively colonizing the midgut and the male reproductive system of the mosquito Anopheles stephensi
Kozakia is a genus of bacteria from the family of Acetobacteraceae. Up to now there is only one species of this genus known.
