A new acid-stable, Fe-oxidizing/O_2-reducing supercomplex spanning both inner and outer membranes, isolated from the extremophile Acidithiobacillus

摘要

Acidithiobacillus ferrooxidans is an acidophilic chemolithoautotrophic gram-negative bacterium that derives energy from the oxidation of Fe(II) ions, elemental sulfur and various sulfur compounds at pH 2 using oxygen as electron acceptor. This organism is the main bacterium used in the industrial extraction of copper and uranium from ores using the microbial leaching technique. The study of this bacterium presents economic and fundamental biological interests. It oxidizes metal sulfides like pyrite, thereby enabling solubilisation and valorization of precious metals. Acidithiobacillus contains various soluble (cytochromes c4, rusticyanin) and membrane-bound (aa_3-type cytochrome c oxidase, cytochrome Cyc2) electron carriers suspected to be involved in electron transfer from Fe(II) ions to molecular oxygen.