Betaproteobacteria is a class of Proteobacteria

Proteobacteria

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....

. Betaproteobacteria are, like all Proteobacteria, gram-negative

Gram-negative

Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

.

The Betaproteobacteria consist of several groups of aerobic or facultative bacteria which are often highly versatile in their degradation capacities, but also contain chemolithotrophic genera (e.g. the ammonia-oxidising genus Nitrosomonas

Nitrosomonas

Nitrosomonas is a genus comprising rod shaped chemoautotrophic bacteria.This rare bacteria oxidizes ammonia into nitrite as a metabolic process. Nitrosomonas are useful in treatment of industrial and sewage waste and in the process of bioremediation. They are important in the nitrogen cycle by...

) and some phototrophs (members of the genera Rhodocyclus and Rubrivivax). Betaproteobacteria play a role in nitrogen fixation in various types of plants, oxidizing ammonium to produce nitrite- an important chemical for plant function. Many of them are found in environmental samples, such as waste water or soil. Pathogenic species within this class are the Neisseriaceae

Neisseriaceae

The Neisseriaceae are a family of Proteobacteria, given their own order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus Neisseria includes 2 important human pathogens, specifically those responsible for gonorrhea and many cases of meningitis...

 (gonorrhea

Gonorrhea

Gonorrhea is a common sexually transmitted infection caused by the bacterium Neisseria gonorrhoeae. The usual symptoms in men are burning with urination and penile discharge. Women, on the other hand, are asymptomatic half the time or have vaginal discharge and pelvic pain...

 and meningitis

Meningitis

Meningitis is inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs...

) and species of the genus Burkholderia

Burkholderia

Burkholderia is a genus of proteobacteria probably best known for its pathogenic members:Burkholderia mallei, responsible for glanders, a disease that occurs mostly in horses and related animals;...

.

Orders and families include:

• Burkholderiales
  Burkholderiales
  The Burkholderiales are an order of Proteobacteria. Like all Proteobacteria, they are gram-negative. They include several pathogenic bacteria, including species of Burkholderia and Bordetella. They also include Oxalobacter and related genera, which are unusual in using oxalic acid as their source...
  
  
  • Alcaligenaceae
    Alcaligenaceae
    The Alcaligenaceae are a family of bacteria, included in the order Burkholderiales. Members are found in water, soil, animals and humans. Some species, like some of Bordetella, are pathogen for humans and for some animals....
    
    
  • Burkholderiaceae
    Burkholderiaceae
    The Burkholderiaceae are a family of bacteria, included in the order Burkholderiales. It includes some pathogenic species, like Burkholderia mallei and Burkholderia pseudomallei .-External links:...
    
    
  • Comamonadaceae
    Comamonadaceae
    The Comamonadaceae are a family of the Beta Proteobacteria. Like all Proteobacteria, they are Gram-negative. They are aerobic and most of the species are motile via flagella and curved rod-shaped.-References:...
    
    
  • Oxalobacteraceae
    Oxalobacteraceae
    The Oxalobacteraceae are a family of bacteria, included in the order Burkholderiales. Like all Proteobacteria, Oxalobacteraceae are gram-negative. The Family includes strict aerobes, strict anaerobes, and also nitrogen-fixing members....
    
    
  • Sutterellaceae
• Ferritrophicales
  • Ferritrophicaceae
• Gallionellales
  • Gallionellaceae
• Hydrogenophilales
  • Hydrogenophilaceae
    Hydrogenophilaceae
    The Hydrogenophilaceae are a family of Betaproteobacteria, with two genera. Like all Proteobacteria they are Gram-negative. Hydrogenophilus are thermophilic, growing around 50 °C and obtaining their energy from oxidizing hydrogen. It includes the genera Hydrogenophilus and Thiobacillus...
    
    
• Methylophilales
  Methylophilaceae
  The Methylophilaceae are a family of Proteobacteria, given their own order. Like all Proteobacteria, they are gram-negative. The cells are slightly curved or straight rod-shaped.-External links:...
  
  
  • Methylophilaceae
    Methylophilaceae
    The Methylophilaceae are a family of Proteobacteria, given their own order. Like all Proteobacteria, they are gram-negative. The cells are slightly curved or straight rod-shaped.-External links:...
    
    
• Neisseriales
  Neisseriaceae
  The Neisseriaceae are a family of Proteobacteria, given their own order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus Neisseria includes 2 important human pathogens, specifically those responsible for gonorrhea and many cases of meningitis...
  
  
  • Neisseriaceae
    Neisseriaceae
    The Neisseriaceae are a family of Proteobacteria, given their own order. While many organisms in the family are mammalian commensals or part of the normal flora, the genus Neisseria includes 2 important human pathogens, specifically those responsible for gonorrhea and many cases of meningitis...
    
    
• Nitrosomonadales
  Nitrosomonadales
  The Nitrosomonadales are a small order of Proteobacteria. Like all Proteobacteria, they are gram-negative. They include Nitrosomonas, Nitrosospira, Gallionella , and Spirillum. The species Spirillum minus causes Rat bite fever.-References:*Garrity, George M.; Brenner, Don J.; Krieg, Noel R.;...
  
  
  • Nitrosomonadaceae
  • Spirillaceae
    Spirillaceae
    Spirillaceae is a family of bacteria. It has been described as a member of Nitrosomonadales, in Betaproteobacteria.It includes the species Spirillum minus which causes Rat bite fever....
    
    
• Procabacteriales
  • Procabacteriaceae
• Rhodocyclales
  Rhodocyclaceae
  The Rhodocyclaceae are a family of gram-negative bacteria. They are given their own order in the beta subgroup of Proteobacteria, and include many genera previously assigned to the family Pseudomonadaceae. The family contains mainly aerobic or denitrifying rod-shaped bacteria, which exhibit very...
  
  
  • Rhodocyclaceae
    Rhodocyclaceae
    The Rhodocyclaceae are a family of gram-negative bacteria. They are given their own order in the beta subgroup of Proteobacteria, and include many genera previously assigned to the family Pseudomonadaceae. The family contains mainly aerobic or denitrifying rod-shaped bacteria, which exhibit very...
    
    
• unclassified Betaproteobacteria
  • Aquamonas
  • Candidatus Accumulibacter
    Candidatus Accumulibacter
    Candidatus Accumulibacter is an unclassified group of Betaproteobacteria that currently contains only a single member, Candidatus Accumulibacter Phosphatis. C. Accumulibacter phosphatis is a common bacterial community member of wastewater treatment plants performing enhanced biological phosphorus...
    
    
  • Candidatus Nitrotoga
  • Candidatus Tremblaya
  • Denitrobacter
  • Ferrovum
  • Imtechium
  • Kinetoplastibacterium
  • Proteinimicrobium
  • Ultramicrobacter