The NitrosomonadalesBoden, R; Hutt, LP, Rae AW (2017) Reclassification of ''Thiobacillus aquaesulis'' (Wood & Kelly, 1995) as ''Annwoodia aquaesulis'' gen. nov., comb. nov., transfer of ''Thiobacillus'' (Beijerinck, 1904) from the ''Hydrogenophilales'' to the ''Nitrosomonadales'', proposal of ''Hydrogenophilalia'' class. nov. within the 'Proteobacteria', and four new families within the orders ''Nitrosomonadales'' and ''Rhodocyclales''. Int J Syst Evol Microbiol 67: 1191-1205 are an order of the class ''

Betaproteobacteria Betaproteobacteria are a class of Gram-negative bacteria, and one of the eight classes of the phylum Pseudomonadota (synonym Proteobacteria). The ''Betaproteobacteria'' are a class comprising over 75 genera and 400 species of bacteria. Togeth ...

'' in the phylum "'' Pseudomonadota''".Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacteriology, Volume Two: The Proteobacteria, Part C: The Alpha-, Beta-, Delta-, and Epsilonproteobacteria. New York, New York: Springer. . Like all members of their class, they are

Gram-negative Gram-negative bacteria are bacteria that do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. They are characterized by their cell envelopes, which are composed of a thin peptidoglycan cell wa ...

. The order is divided into six families:
'' Nitrosomonadaceae'' (type family) comprises the genera ''

Nitrosomonas ''Nitrosomonas'' is a genus of Gram-negative bacteria, belonging to the Betaproteobacteria. It is one of the five genera of ammonia-oxidizing bacteria and, as an obligate chemolithoautotroph, uses ammonia (NH3) as an energy source and carbon di ...

'' (type genus), '' Nitrosolobus'' and '' Nitrosospira''.
'' Methylophilaceae'' comprises the genera '' Methylophilus'' (type genus), '' Methylobacillus'' and '' Methylovorus''.
''

Spirillaceae Spirillaceae is a family in the order '' Nitrosomonadales'' in the class ''Betaproteobacteria'' of the bacteria. Only one genus, ''Spirillum ''Spirillum'' is a genus of Gram-negative bacteria in the family '' Spirillaceae'' of the '' Nitros ...

'' comprises the genus ''

Spirillum ''Spirillum'' is a genus of Gram-negative bacteria in the family '' Spirillaceae'' of the '' Nitrosomonadales'' of the ''Betaproteobacteria''.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual o ...

'' (type genus)
'' Thiobacillaceae'' comprises the genera ''

Thiobacillus ''Thiobacillus'' is a genus of Gram-negative Betaproteobacteria. ''Thiobacillus thioparus'' is the type species of the genus, and the type strain thereof is the StarkeyT strain, isolated by Robert Starkey in the 1930s from a field at Rutgers Un ...

'' (type genus), '' Annwoodia'', '' Sulfuritortus''.
'' Gallionellaceae'' comprises the genera '' Gallionella'' (type genus), '' Ferriphaselus'', '' Sulfuriferula'', '' Sulfurirhabdus'' and '' Sulfuricella''.
'' Sterolibacteraceae'' comprises the genera '' Sterolibacterium'', '' Sulfurisoma'', '' Denitratisoma'', '' Sulfuritalea'', '' Georgfuchsia'', '' Sulfurisoma'' and '' Methyloversatilis''. Members of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

'' oxidize ammonium ions into nitrite, - a process called

nitrification ''Nitrification'' is the biological oxidation of ammonia to nitrite followed by the oxidation of the nitrite to nitrate occurring through separate organisms or direct ammonia oxidation to nitrate in comammox bacteria. The transformation of am ...

- and are important in the nitrogen cycle. Other

autotroph An autotroph or primary producer is an organism that produces complex organic compounds (such as carbohydrates, fats, and proteins) using carbon from simple substances such as carbon dioxide,Morris, J. et al. (2019). "Biology: How Life Wo ...

ic genera such as ''

'' and '' Annwoodia'' oxidize reduced inorganic sulfur ions such as

thiosulfate Thiosulfate ( IUPAC-recommended spelling; sometimes thiosulphate in British English) is an oxyanion of sulfur with the chemical formula . Thiosulfate also refers to the compounds containing this anion, which are the salts of thiosulfuric acid, ...

and sulfide into

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ...

and have key roles in the sulfur cycle.

Methylotroph Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl e ...

s such as '' Methylophilus'' oxidize compounds such as methanol into

carbon dioxide Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...

and are key to the

carbon cycle The carbon cycle is the biogeochemical cycle by which carbon is exchanged among the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth. Carbon is the main component of biological compounds as well as a major componen ...

. '' Gallionella'' and '' Ferriphaselus'' oxidise

ferrous In chemistry, the adjective Ferrous indicates a compound that contains iron(II), meaning iron in its +2 oxidation state, possibly as the divalent cation Fe2+. It is opposed to " ferric" or iron(III), meaning iron in its +3 oxidation state, suc ...

iron (Fe²⁺) ions into

ferric hydroxide Iron(III) oxide-hydroxide or ferric oxyhydroxideA. L. Mackay (1960): "β-Ferric Oxyhydroxide". ''Mineralogical Magazine'' (''Journal of the Mineralogical Society''), volume 32, issue 250, pages 545-557. is the chemical compound of iron, oxygen, ...

(Fe(OH)₃) during

ic growth, and thus have roles in the

and the

iron cycle The iron cycle (Fe) is the biogeochemical cycle of iron through the atmosphere, hydrosphere, biosphere and lithosphere. While Fe is highly abundant in the Earth's crust, it is less common in oxygenated surface waters. Iron is a key micronutrient i ...

. As such, the ''Nitrosomonadales'' are critical to

biogeochemical Biogeochemistry is the scientific discipline that involves the study of the chemical, physical, geological, and biological processes and reactions that govern the composition of the natural environment (including the biosphere, the cryosphere, th ...

cycling of the elements and many species have key roles in principal biochemical processes.

References

External links

Nitrosomonadales
J.P. Euzéby: List of Prokaryotic names with Standing in Nomenclature
''Nitrosomonas''
MicrobeWki Betaproteobacteria {{Betaproteobacteria-stub