''Halothiobacillus'' is a genus in the ''

Gammaproteobacteria Gammaproteobacteria is a class of bacteria in the phylum Pseudomonadota (synonym Proteobacteria). It contains about 250 genera, which makes it the most genera-rich taxon of the Prokaryotes. Several medically, ecologically, and scientifically imp ...

''. Both species are

obligate aerobic {{wiktionary, obligate As an adjective, obligate means "by necessity" (antonym ''facultative'') and is used mainly in biology in phrases such as: * Obligate aerobe, an organism that cannot survive without oxygen * Obligate anaerobe, an organism that ...

bacteria; they require oxygen to grow. They are also halotolerant; they live in environments with high concentrations of salt or other solutes, but don't require them in order to grow. The type species of this genus, '' Halothiobacillus neapolitanus'' used to be members of the genus '' Thiobacillus'', before they were reclassified in 2000.Kelly, D.P., and Wood, A.P. "Reclassification of some species of ''Thiobacillus'' to the newly designated genera '' Acidithiobacillus'' gen. nov., ''Halothiobacillus'' gen. nov. and '' Thermithiobacillus'' gen. nov." Int. J. Syst. Evol. Microbiol. (2000) 50:489-500. A further two former '' Thiobacillus'' spp. were also reclassified as ''

Halothiobacillus halophilus ''Halothiobacillus'' is a genus in the ''Gammaproteobacteria''. Both species are obligate aerobic bacteria; they require oxygen to grow. They are also halotolerant; they live in environments with high concentrations of salt or other solutes, bu ...

'' and ''

Halothiobacillus hydrothermalis ''Halothiobacillus'' is a genus in the ''Gammaproteobacteria''. Both species are obligate aerobic bacteria; they require oxygen to grow. They are also halotolerant; they live in environments with high concentrations of salt or other solutes, bu ...

'', both of which were obligate

halophile The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, ...

s rather than being halotolerant and showed comparatively low

16S rRNA 16S rRNA may refer to: * 16S ribosomal RNA 16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The g ...

gene identity to '' Halothiobacillus neapolitanus'' and so were reclassified to the newly designated genus '' Guyparkeria'' in 2017, as '' Guyparkeria halophila'' and '' Guyparkeria hydrothermalis''.

Environmental importance

''Halothiobacillus'' spp. and other chemolithoautotrophic organisms play an important role in global carbon and sulfur cycles. They are able to depend entirely on inorganic compounds (CO₂ and reduced sulfur) for their carbon and energy needs, but can assimilate some Krebs cycle intermediates during autotrophic growth.

Species

* ''

Halothiobacillus kellyi ''Halothiobacillus'' is a genus in the ''Gammaproteobacteria''. Both species are obligate aerobic bacteria; they require oxygen to grow. They are also halotolerant; they live in environments with high concentrations of salt or other solutes, bu ...

'' * '' Halothiobacillus neapolitanus'' (basonym: ''Thiobacillus neapolitanus''), the type strain of which is ParkerX^T, isolated from decomposing concrete in the sewer outfall of Melbourne,

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

by Cecil David 'Guy' Parker in the 1940s - this strain is now a common model organism for autotrophy research, in particular study of carboxysomes and their role in carbon concentration and maintaining RuBisCO efficiency during autotrophic growth.

References

External links

Genome page for ''Halothiobacillus neapolitanus c2'' at the Joint Genome Institute
Bacteria genera Halothiobacillaceae {{Chromatiales-stub