''Alicyclobacillus acidocaldarius'' is a species of Gram positive, strictly aerobic, bacterium. The bacteria are acidophilic, thermophilic, and produce endospores. The first identified strains of ''A. acidocaldarius'' were from

geyser A geyser (, ) is a spring characterized by an intermittent discharge of water ejected turbulently and accompanied by steam. As a fairly rare phenomenon, the formation of geysers is due to particular hydrogeological conditions that exist only in ...

s in Yellowstone National Park and

fumerole A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

soil in

Hawaii Volcano National Park Hawaii ( ; haw, Hawaii or ) is a U.S. state, state in the Western United States, Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is ...

. The species was originally classified as ''Bacillus acidocaldarius'' in 1971, but further

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 ...

studies found that the species belonged in the newly created genus ''Alicyclobacillus''. The species name is derived from the Latin ''acidum'' (acid) and ''caldarius'' (pertaining to warm or hot), referring to the acidic and high temperature environments from which it was first isolated. Thomas D. Brock was one of the researchers who first categorized the species; his discovery of '' Thermus aquaticus'' allowed for other researchers to discover Taq polymerase and polyermase chain reaction (PCR). A strain of ''A. acidocaldarius'' has been isolated from thermally heated soils of Mount Rittmann in Antarctica. ''Alicyclobacillus acidocaldarius'' was among the first three species reclassified from the genus '' Bacillus'' to the newly created ''Alicyclobacillus'' in 1992, along with '' A. acidoterrestris'' and '' A. cycloheptanicus''. The optimum growth temperature for ''A. acidocaldarius'' is 60-65 °C, and can grow in the 45-70 °C range. The optimum pH is 3.0-4.0, and can grow in pH 2.0-6.0.

References

Gram-positive bacteria Bacteria described in 1992 Bacillales {{bacilli-stub