{{Short description|Genus of bacteria}} {{Automatic taxobox | image = Carboxysomes EM.jpg | image_caption = ''Halothiobacillus neapolitanus'' with carboxysomes | taxon = Halothiobacillus | authority = Kelly and Wood 2000 | subdivision_ranks = Species | subdivision = ''Halothiobacillus kellyi''<br> ''Halothiobacillus neapolitanus''<br> }}
'''''Halothiobacillus''''' is a genus in the class 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, 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.<ref name=KellyWood2000>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.</ref> A further two former ''Thiobacillus'' spp. were also reclassified as ''Halothiobacillus halophilus'' and ''Halothiobacillus hydrothermalis'', both of which were obligate halophiles rather than being halotolerant and showed comparatively low 16S rRNA gene identity to ''Halothiobacillus neapolitanus'' and so were reclassified to the newly designated genus ''Guyparkeria'' in 2017, as ''Guyparkeria halophila'' and ''Guyparkeria hydrothermalis''.<ref name=Boden2017>{{cite journal|author=Boden R |title=Reclassification of ''Halothiobacillus hydrothermalis'' and ''Halothiobacillus halophilus'' to ''Guyparkeria'' gen. nov. in the ''Thioalkalibacteraceae'' fam. nov., with emended descriptions of the genus ''Halothiobacillus'' and family ''Halothiobacillaceae''. |journal=International Journal of Systematic and Evolutionary Microbiology |volume=67 |date=2017 |pages=3919–3928 |url=http://ijs.microbiologyresearch.org/pubmed/content/journal/ijsem/10.1099/ijsem.0.002222 |pmid=28884673 |access-date=9 December 2017 |doi=10.1099/ijsem.0.002222|doi-access=free |hdl=10026.1/9982 |hdl-access=free |url-access=subscription }}</ref>
==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 (CO<sub>2</sub> and reduced sulfur) for their carbon and energy needs, but can assimilate some Krebs cycle intermediates during autotrophic growth.<ref name=Boden2017 />
==Species== * ''Halothiobacillus kellyi'' * ''Halothiobacillus neapolitanus'' (basonym: ''Thiobacillus neapolitanus''<ref name=KellyWood2000 />), the type strain of which is ParkerX<sup>T</sup>, isolated from decomposing concrete in the sewer outfall of Melbourne, Australia 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.<ref name=Boden2017 />
==References== {{Reflist}}
== External links == * [https://web.archive.org/web/20150712063731/http://genome.jgi-psf.org/halne/halne.home.html Genome page for ''Halothiobacillus neapolitanus c2'' at the Joint Genome Institute]
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Category:Bacteria genera Category:Halothiobacillaceae
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