Acidithiobacillus ferrooxidans

Acidithiobacillus ferrooxidans is a bacterium that sustains its life cycle at extremely low pH values, and it is one of the very few organisms that gain energy from oxidating ferrous iron (Fe +II). It can make copper from ores water-soluble, and it can sequester both carbon and nitrogen from the atmosphere.

Not only is A. ferrooxidans the best-studied of the acidophilic bacteria. During mining activities, the bacterium plays a crucial role in producing harmful acidic and metal-rich drainage water through the dissolution of sulfide minerals, but it also recovers precious dissolved metals.

The gram-negative bacterium grows best at 30 °C at pH 2 and Fe 2+ concentrations of 10-1 M, but growth still occurs at pH values of less than 1.

Genetics
The ATCC 23270 type strain has one circular chromosome of 2.9 million base pairs and a G+C content of 59%. Genome sequencing has shown 2070 genes that code for a protein with a known function, while 1147 hypothetical proteins have been found. The bacterium contains a gene that makes it toluene-resistant. Genes for chemotaxis and locomotion (flagella) have not been observed.