''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 genus-rich taxon of the Prokaryotes. Several medically, ecologically, and scienti ...

''. 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, 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 ''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 U ...

'', 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 ''Acidithiobacillus'' is a genus of the '' Acidithiobacillia'' in the phylum "'' Pseudomonadota''". This genus includes ten species of acidophilic microorganisms capable of sulfur and/or iron oxidation: ''Acidithiobacillus albertensis, Acidithiob ...

'' gen. nov., ''Halothiobacillus'' gen. nov. and ''

Thermithiobacillus ''Thermithiobacillus'' is a genus of nonsporeforming, rod-shaped, Gram-negative bacteria. The name derives from the Latin ''thermae'', for warm baths, and the Classical Greek θείος, ''theios'' for sulfur. The type species of this genus was ...

'' gen. nov." Int. J. Syst. Evol. Microbiol. (2000) 50:489-500. A further two former ''

'' spp. were also reclassified as '' Halothiobacillus halophilus'' and '' Halothiobacillus hydrothermalis'', both of which were obligate

halophile A halophile (from the Greek word for 'salt-loving') is an extremophile that thrives in high salt In common usage, salt is a mineral composed primarily of sodium chloride (NaCl). When used in food, especially in granulated form, it is more ...

s rather than being halotolerant and showed comparatively low

16S rRNA 16S ribosomal RNA (or 16Svedberg, 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 genes coding for it are referred to as ...

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 The citric acid cycle—also known as the Krebs cycle, Szent–Györgyi–Krebs cycle, or TCA cycle (tricarboxylic acid cycle)—is a series of biochemical reactions that release the energy stored in nutrients through acetyl-CoA oxidation. The e ...

intermediates during

autotrophic An autotroph is an organism that can convert abiotic sources of energy into energy stored in organic compounds, which can be used by other organisms. Autotrophs produce complex organic compounds (such as carbohydrates, fats, and proteins) us ...

growth.

Species

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

Melbourne Melbourne ( , ; Boonwurrung language, Boonwurrung/ or ) is the List of Australian capital cities, capital and List of cities in Australia by population, most populous city of the States and territories of Australia, Australian state of Victori ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

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 Ribulose-1,5-bisphosphate carboxylase/oxygenase, commonly known by the abbreviations RuBisCo, rubisco, RuBPCase, or RuBPco, is an enzyme () involved in the light-independent (or "dark") part of photosynthesis, including the carbon fixation by wh ...

efficiency during autotrophic growth.

References

External links

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