From MicrobeWiki, the student-edited microbiology resource
A Microbial Biorealm page on the genus Thiobacillus
Higher order taxa:
Bacteria; Proteobacteria; Betaproteobacteria; Hydrogenophilales; Hydrogenophilaceae
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, preferring a pH of 1.5 to 2.5. A few species, however, only grow in a neutral pH.
At present there is not an extensive body of research on the Thiobacillus genome structure.
Cell Structure and Metabolism
Thiobacillus are colorless, rod-shaped, Gram-negative bacteria with polar flagella. They possess an iron oxidase, which allows them to metabolize metal ions such as ferrous iron:
Fe2+ + 1/2 O2 + 2H+ --> Fe3+ + H2O
Thiobacillus are strictly aerobic bacteria. All species are respiratory organisms.
Thiobacillus are obligate autotrophic organisms, meaning they require inorganic molecules as an electron donor and inorganic carbon (such as carbon dioxide) as a source. They obtain nutrients by oxidizing iron and sulfur with O2.
Thiobacillus do not form spores; they are Gram-negative Proteobacteria. Their life cycle is typical of bacteria, with reproduction by cell fission.
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.
Gardner, Murray N., Shelly M. Deane, and Douglas E. Rawlings. "Isolation of a New Broad-Host-Range IncQ-Like Plasmid, pTC-F14, from the Acidophilic Bacterium Acidithiobacillus caldus and Analysis of the Plasmid Replicon." J Bacteriol. 2001 June; 183(11): 3303–3309.
Levicán, Gloria, Patrice Bruscella, Maritza Guacunano, Carolina Inostroza, Violaine Bonnefoy, David S. Holmes, and Eugenia Jedlicki. "Characterization of the petI and res Operons of Acidithiobacillus ferrooxidans." J Bacteriol. 2002 March; 184(5): 1498–1501.
Peccia, Jordan, Eric A. Marchand, Joann Silverstein, and Mark Hernandez. "Development and Application of Small-Subunit rRNA Probes for Assessment of Selected Thiobacillus Species and Members of the Genus Acidiphilium." Appl Environ Microbiol. 2000 July; 66(7): 3065–3072.