Figure 1

A. ferrooxidans and its proposed role in bioleaching. The chemolithoautotrophic metabolism of A. ferrooxidans results in the oxidation/reduction of iron and sulfur compounds and the solubilization of copper and other commercially valuable metals in a process called bioleaching or biomining. It also results in the production of acidified solutions in pristine environments and acid mine drainage in bioleaching operations. A) Model of copper bioleaching by A. ferrooxidans. B) Oxidation/reduction reactions carried out by A. ferrooxidans. The scheme provided here presents the basic concepts of bioleaching and further details are provided in the review [4]. C) Acid mine drainage in the Rio Tinto, Spain, derived from naturally occurring pyritic ore bodies and abandoned mine workings initiated in pre-Roman times [3]. D) Commercial bioleaching heap for copper recovery, Chile. 3PG: 3-phosphoglycerate.