''Spirillum'' is a genus of

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

bacteria in the family '' Spirillaceae'' of the '' Nitrosomonadales'' of the ''

Betaproteobacteria ''Betaproteobacteria'' are a class of Gram-negative bacteria, and one of the six classes of the phylum '' Pseudomonadota'' (synonym Proteobacteria). Metabolism The ''Betaproteobacteria'' comprise over 75 genera and 400 species. Together, they ...

''.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. pp. 354–361. .Podkopaeva (D.), Grabovich (M.), Kuever (J.), Lysenko (A.M.), Tourova (T.P.), Kolganova (T.V.) and Dubinia (G.): Proposal of Spirillum winogradskyi sp. nov., a novel microaerophilic species, an amended description of the genus Spirillum and Request for an Opinion regarding the status of the species Spirillum volutans Ehrenberg 1832. Int. J. Syst. Evol. Microbiol., 2009, 59, 2916-2920. There are two species of ''Spirillum'' with validly or effectively published names - '' Spirillum winogradskyi'' and '' Spirillum volutans''. Other "species" classified as ''Spirillum'' such as "'' Spirillum minus''", "'' Spirillum pleomorphum''", and "'' Spirillum pulli''" are of uncertain phylogeny and in any case, these are names that have never been validly or effectively published and thus have no standing in

nomenclature Nomenclature (, ) is a system of names or terms, or the rules for forming these terms in a particular field of arts or sciences. (The theoretical field studying nomenclature is sometimes referred to as ''onymology'' or ''taxonymy'' ). The principl ...

Morphology

Members of the genus ''Spirillum'' are large, elongate, spiral shaped, rigid cells. Some have tufts of amphitrichous flagella at both poles. They are microaerophilic and usually found in stagnant freshwater rich in organic matter.

References

External links

* Nitrosomonadales Bacteria genera Taxa named by Christian Gottfried Ehrenberg {{Betaproteobacteria-stub