Acidithiobacillus ferrooxidans
Introduction
Acidithiobacillus ferrooxidans is a Gram-negative, rod-shaped bacteria that is known for its role in bioleaching, the process of extracting metals from their ores. This bacterium is acidophilic, meaning it thrives in highly acidic environments, and is capable of oxidizing ferrous iron and sulfur compounds to derive energy.
Taxonomy and Phylogeny
The bacterium was initially classified under the genus Thiobacillus, but was later reclassified to the newly created genus Acidithiobacillus due to its distinct characteristics. Acidithiobacillus ferrooxidans is one of the seven species of the genus Acidithiobacillus, which is a part of the class Acidithiobacillia in the phylum Proteobacteria.
Morphology and Physiology
Acidithiobacillus ferrooxidans is a rod-shaped bacterium with a size of approximately 0.5-1.5 µm in width and 1-2 µm in length. It is a Gram-negative bacterium, meaning it does not retain the crystal violet stain used in the Gram staining method. The bacterium is motile, possessing a single polar flagellum that allows it to move towards nutrient sources.
Metabolism
Acidithiobacillus ferrooxidans is a chemolithoautotroph, meaning it derives energy from the oxidation of inorganic compounds and uses carbon dioxide as its primary carbon source. This bacterium is capable of oxidizing ferrous iron (Fe2+) to ferric iron (Fe3+), as well as oxidizing reduced sulfur compounds, such as elemental sulfur and tetrathionate.
Ecological Role
Acidithiobacillus ferrooxidans plays a significant role in the biogeochemical cycling of sulfur and iron. It is also involved in the formation of acid mine drainage, a process that results in the release of heavy metals into the environment. Furthermore, this bacterium is used in bioleaching, a process used in the mining industry to extract metals from their ores.
Industrial Applications
Due to its ability to oxidize iron and sulfur compounds, Acidithiobacillus ferrooxidans is used in the mining industry for the extraction of metals from their ores, a process known as bioleaching. This bacterium is also used in the treatment of sewage and industrial waste, as well as in the recovery of gold from electronic waste.