Acidithiobacillus thiooxidans
| Acidithiobacillus thiooxidans | |
|---|---|
| Scientific classification | |
| Kingdom: | Bacteria |
| Phylum: | Proteobacteria |
| Class: | Acidithiobacillia |
| Order: | Acidithiobacillales |
| Family: | Acidithiobacillaceae |
| Genus: | Acidithiobacillus |
| Species: | A. thiooxidans |
| Binomial name | |
|
Acidithiobacillus thiooxidans (Kelly and Wood 2000) |
|
| Type strain | |
| DSM 17318 ATCC 19377T DAMS |
|
| Synonyms | |
|
Thiobacillus concretivorus |
|
Thiobacillus concretivorus
Kelly & Harrison 1989
Thiobacillus thiooxidans
Kelly & Wood 2000
Acidithiobacillus thiooxidans, formerly known as Thiobacillus thiooxidans until its reclassification into the newly designated genus Acidithiobacillus of the gamma subclass of Proteobacteria, is a Gram-negative, rod-shaped bacterium that uses sulfur as its primary energy source. It is mesophilic, with a temperature optimum of 28 °C. This bacterium is commonly found in soil, sewer pipes, and cave biofilms called snottites.A. thiooxidans is used in the mining technique known as bioleaching, where metals are extracted from their ores through the action of microbes.
A. thiooxidans is a Gram-negative, rod-shaped bacterium with rounded ends that occurs in nature either as singlecells, as is the most common case, or sometimes in pairs, but rarely in triplets. Its motility is due to a polar flagellum. It is an obligate acidophile with an optimal pH less than 4.0, but it also qualifies as an obligate aerobe and chemolithotroph. Described as a colorless, sulfur-oxidizing bacterium, A. thiooxidans does not accumulate sulfur either within or outside of its very small cells, which have an average size around 0.5 µm in diameter and 1 µm or less in length.
A. thiooxidans has so far not grown on agar or other solid media, instead it prefers liquid media with a strong, evenly dispersed clouding throughout, and it produces no sediment formation or surface growth. Although it does not grow on traditional organic media, it will not be harmed by a medium containing peptone or glucose. Media best suited for its growth are those that are inorganic and allow A. thiooxidans to use sulfur as a source of energy. The following characteristic reactions accompany the growth of A. thiooxidans in the presence of tricalcium phosphate: the layer on the surface of the medium formed by sulfur tends to drop to the bottom, tricalcium phosphate is dissolved by the product of sulfur oxidation, sulfuric acid, giving soluble phosphate and CaSO4 + 2 H2O, and radiating monoclinic crystals that hang from the sulfur particles floating on the medium surface or protruding upward from the bottom are formed by the precipitation of calcium sulfate. The medium becomes acidic with a pH around 2.8 and remains stationary until all the calcium phosphate has been dissolved. Anything with the tendency to change the medium to an alkaline state would be considered harmful to the uniform growth of A. thiooxidans, but if it is left unharmed by an excess of acid or alkali, numerous consecutive generations may be kept alive on the liquid media.
...
Wikipedia