Thiobacillus
From MicrobeWiki, the student-edited microbiology resource
A Microbial Biorealm page on the genus Thiobacillus
Contents |
Classification
Higher order taxa:
Bacteria; Proteobacteria; Betaproteobacteria; Hydrogenophilales; Hydrogenophilaceae
Species:
Thiobacillus aquaesulis, T. ferrooxidans, T. denitrificans
Description and Significance
The genus Thiobacillus is also known under the name of Acidithiobacillus. Thiobacillus ferrooxidans are airborne bacteria. This genus is thermophilic, preferring temperatures of 45-50 degrees Celsius. In addition, this is an acidophilic genus, perferring a pH of 1.5 to 2.5. A few species, however, only grow in a neutral pH.
Genome Structure
At present there is not an extensive body of research on the Thiobacillus genome strucutre.
Cell Structure and Metabolism
Thiobacillus are colorless, rod-shaped, Gram-negative bacteria with polar flagella. They posess an iron oxidase, which allows them to break down metal ions. Thiobacillus are strictly aerobic bacteria. All species are respiratory organisms.
Thiobacillus are obligate autotrophic organisms, meaning they require organic carbon both as an electron and carbon source. They obtain nutrients by oxidizing iron and sulfur.
Thiobacillus do not form spores. Their life cycle is typical of bacteria, with reproduction by division.
Ecology
Thiobacillus ferrooxidans is the most common type of bacteria in mine waste piles. This organism is acidophilic (acid loving), and increases the rate of pyrite oxidation in mine tailings piles and coal deposits. It oxidies iron and inorganic sulfur compounds. The oxidation process can be harmful, as it produces sulfuric acid, which is a major pollutant. However, it can also be beneficial in recovering materials such as copper and uranium. It has been suggested that T. ferrooxidans forms a symbiotic relationship with members of the genus Acidiphilium, a bacterial capable of iron reduction. Other species of Thiobacillus grow in water and sediment; there are both freshwater and marine strains.
References
Horan, Jim. "Acid Mine Drainage Experiments." 3 December 1999. Accessed 22 July 2005.