Editing Pseudomonadota (section)

==Characteristics==
Pseudomonadota are a diverse group. Though some species may stain Gram-positive or Gram-variable in the laboratory, they are nominally [[Gram-negative]]. Their unique [[Bacterial outer membrane|outer membrane]] is mainly composed of [[lipopolysaccharide]]s, which helps differentiate them from the Gram-positive species.<ref>{{Cite journal |last1=Silhavy |first1=Thomas J. |last2=Kahne |first2=Daniel |last3=Walker |first3=Suzanne |date=2010-05-01 |title=The Bacterial Cell Envelope |url=http://cshperspectives.cshlp.org/content/2/5/a000414 |journal=Cold Spring Harbor Perspectives in Biology |language=en |volume=2 |issue=5 |pages=a000414 |doi=10.1101/cshperspect.a000414 |issn=1943-0264 |pmc=2857177 |pmid=20452953}}</ref> Most Pseudomonadota are motile and move using flagella. Many move about using [[Flagellum|flagella]], but some are nonmotile, or rely on [[bacterial gliding]].<ref name=":4">{{Cite web |title=Pseudomonadota Garrity et al., 2021 |url=https://www.gbif.org/species/113662549 |access-date=2024-04-18 |website=www.gbif.org |language=en}}</ref>

Pseudomonadota have a wide variety of [[metabolism]] types. Most are facultative or obligate [[Anaerobic organism|anaerobes]], [[Chemolithoautotrophic|chemolithoautotrophs]], and [[Heterotrophic|heterotrophs]], though numerous exceptions exist. A variety of distantly related genera within the Pseudomonadota obtain their energy from light through conventional [[photosynthesis]] or [[anoxygenic photosynthesis]].<ref name=":4" />

The [[Acidithiobacillia]] contain only sulfur, iron, and uranium-oxidizing [[autotroph]]s. The type order is the [[Acidithiobacillales|Acidithiobacillaceae]], which includes five different ''Acidithiobacillus'' species used in the mining industry. In particular, these microbes assist with the process of [[bioleaching]], which involves microbes assisting in metal extraction from mining waste that typically extraction methods cannot remove.<ref name=":6">{{Citation |last1=Kelly |first1=Donovan P. |title=The Family Acidithiobacillaceae |date=2014 |work=The Prokaryotes: Gammaproteobacteria |pages=15–25 |editor-last=Rosenberg |editor-first=Eugene |url=https://doi.org/10.1007/978-3-642-38922-1_250 |access-date=2024-04-18 |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/978-3-642-38922-1_250 |isbn=978-3-642-38922-1 |last2=Wood |first2=Ann P. |editor2-last=DeLong |editor2-first=Edward F. |editor3-last=Lory |editor3-first=Stephen |editor4-last=Stackebrandt |editor4-first=Erko}}</ref>

Some [[Alphaproteobacteria]] can grow at very low levels of nutrients and have unusual morphology within their life cycles. Some form stalks to help with colonization, and form buds during cell division. Others include agriculturally important bacteria capable of inducing nitrogen fixation in symbiosis with plants. The type order is the [[Caulobacterales]], comprising stalk-forming bacteria such as ''[[Caulobacter]]''.<ref name=":5">{{Citation |last1=Bandopadhyay |first1=Sreejata |title=Soil bacteria and archaea |date=2024 |work=Soil Microbiology, Ecology and Biochemistry |pages=41–74 |url=https://doi.org/10.1016/b978-0-12-822941-5.00003-x |access-date=2024-04-18 |publisher=Elsevier |doi=10.1016/b978-0-12-822941-5.00003-x |isbn=978-0-12-822941-5 |last2=Shade |first2=Ashley}}</ref> The [[mitochondria]] of eukaryotes are thought to be descendants of an alphaproteobacterium.<ref>{{Cite journal |last1=Roger |first1=Andrew J. |last2=Muñoz-Gómez |first2=Sergio A. |last3=Kamikawa |first3=Ryoma |date=November 2017 |title=The Origin and Diversification of Mitochondria |journal=Current Biology |volume=27 |issue=21 |pages=R1177–R1192 |doi=10.1016/j.cub.2017.09.015 |pmid=29112874 |bibcode=2017CBio...27R1177R |issn=0960-9822|doi-access=free}}</ref>

The [[Betaproteobacteria]] are highly metabolically diverse and contain [[chemolithoautotroph]]s, [[photoautotroph]]s, and generalist [[heterotroph]]s. The type order is the [[Burkholderiales]], comprising an enormous range of metabolic diversity, including [[opportunistic pathogen]]s. These pathogens are primary for both humans and animals, such as the horse pathogen ''Burkholderia mallei'', and ''Burkholderia cepacia'' which causes respiratory tract infections in people with cystic fibrosis.<ref>{{Citation |last=Coenye |first=Tom |title=The Family Burkholderiaceae |date=2014 |work=The Prokaryotes: Alphaproteobacteria and Betaproteobacteria |pages=759–776 |editor-last=Rosenberg |editor-first=Eugene |url=https://doi.org/10.1007/978-3-642-30197-1_239 |access-date=2024-04-18 |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/978-3-642-30197-1_239 |isbn=978-3-642-30197-1 |editor2-last=DeLong |editor2-first=Edward F. |editor3-last=Lory |editor3-first=Stephen |editor4-last=Stackebrandt |editor4-first=Erko}}</ref>

The [[Gammaproteobacteria]] are one of the largest classes in terms of genera, containing approximately 250 validly published names.<ref name=":3" /> The type order is the [[Pseudomonadales]], which include the genera ''[[Pseudomonas]]'' and the nitrogen-fixing ''[[Azotobacter]]'', along with many others. Besides being a well-known pathogenic genus, ''Pseudomonas'' is also capable of biodegradation of certain materials, like cellulose.<ref name=":5" />

The [[Hydrogenophilalia]] are thermophilic chemoheterotrophs and autotrophs.<ref>{{Cite journal |last1=Wakai |first1=Satoshi |last2=Masanari |first2=Misa |last3=Ikeda |first3=Takumi |last4=Yamaguchi |first4=Naho |last5=Ueshima |first5=Saori |last6=Watanabe |first6=Kaori |last7=Nishihara |first7=Hirofumi |last8=Sambongi |first8=Yoshihiro |date=April 2013 |title=Oxidative phosphorylation in a thermophilic, facultative chemoautotroph, H ydrogenophilus thermoluteolus, living prevalently in geothermal niches |url=https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/1758-2229.12005 |journal=Environmental Microbiology Reports |language=en |volume=5 |issue=2 |pages=235–242 |doi=10.1111/1758-2229.12005 |pmid=23584967 |bibcode=2013EnvMR...5..235W |issn=1758-2229}}</ref> The bacteria typically use hydrogen gas as an electron donor, but can also use reduced sulfuric compounds. Because of this ability, scientists have begun to use certain species of Hydrogenophilalia to remove sulfides that contaminate industrial wastewater systems. The type order is the [[Hydrogenophilales|Hydrogenophilaceae]] which contains the genera ''Thiobacillus, Petrobacter, Sulfuricella,'' ''Hydrogenophilus'' and ''Tepidiphilus''. Currently, no members of this class have been identified as pathogenic.<ref>{{Citation |last1=Orlygsson |first1=Johann |title=The Family Hydrogenophilaceae |date=2014 |work=The Prokaryotes: Alphaproteobacteria and Betaproteobacteria |pages=859–868 |editor-last=Rosenberg |editor-first=Eugene |url=https://doi.org/10.1007/978-3-642-30197-1_244 |access-date=2024-04-18 |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/978-3-642-30197-1_244 |isbn=978-3-642-30197-1 |last2=Kristjansson |first2=Jakob K. |editor2-last=DeLong |editor2-first=Edward F. |editor3-last=Lory |editor3-first=Stephen |editor4-last=Stackebrandt |editor4-first=Erko}}</ref>

The [[Zetaproteobacteria]] are the [[Microbial metabolism#Ferrous iron (Fe2+) oxidation|iron-oxidizing]] [[Neutrophile|neutrophilic]] [[Chemolithotrophic|chemolithoautotrophs]], distributed worldwide in estuaries and marine habitats.<ref name=":4" /> This group is so successful in its environment due to their microaerophilic nature. Because they require less oxygen than what is present in the atmosphere, they are able to compete with the abiotic iron(II) oxidation that is already occurring in the environment.<ref>{{Cite journal |url=https://academic.oup.com/femsec/article/95/4/fiz015/5304609 |access-date=2024-04-18 |journal=FEMS Microbiology Ecology |doi=10.1093/femsec/fiz015 |pmc=6443915 |pmid=30715272 |title=The Fe(II)-oxidizing ''Zetaproteobacteria'': Historical, ecological and genomic perspectives |date=2019 |volume=95 |issue=4 | vauthors = McAllister SM, Moore RM, Gartman A, Luther GW, Emerson D, Chan CS}}</ref> The only confirmed type order for this class is the [[Mariprofundales|Mariprofundaceae]], which does not contain any known pathogenic species.<ref>{{Citation |last1=Moreira |first1=Ana Paula B. |title=The Family Mariprofundaceae |date=2014 |work=The Prokaryotes: Deltaproteobacteria and Epsilonproteobacteria |pages=403–413 |editor-last=Rosenberg |editor-first=Eugene |url=https://doi.org/10.1007/978-3-642-39044-9_378 |access-date=2024-04-18 |place=Berlin, Heidelberg |publisher=Springer |language=en |doi=10.1007/978-3-642-39044-9_378 |isbn=978-3-642-39044-9 |last2=Meirelles |first2=Pedro M. |last3=Thompson |first3=Fabiano |editor2-last=DeLong |editor2-first=Edward F. |editor3-last=Lory |editor3-first=Stephen |editor4-last=Stackebrandt |editor4-first=Erko}}</ref>