The geomicrobiology of biomining

Metals have a pivotal role in our lives, due to their broad use in a range of industrial and domestic applications and in emerging technologies. Biomining, which uses microorganisms to solubilize metals, is considered an environmentally friendly alternative to conventional pyro- and hydrometallurgical extractive methods. Biomining has been applied on an industrial scale to process sulfidic metal ores and gold concentrates, using acidophilic chemolithotrophic prokaryotes. Due to the increasing global demand for metals and the rapid depletion of global reserves, novel biomining applications have been under development in recent years. Biomining of metals from non-sulfidic minerals (such as nickel laterites), as well as deep-buried or deep-sea minerals using chemolithotrophic acidophiles, is gaining attention. Biomining applications are being developed for electronic waste recycling, investigating also the potential of cyanogenic bacteria and organic acid-generating fungi. This chapter describes the microbiology of biomining, focusing on industrially relevant recovery of metals from mineral ores and waste materials. Additionally, the microbiology in biomining operations, solid mine wastes, and acid mine drainage, which results from uncontrolled microbially catalyzed sulfide oxidation in mine wastes, is discussed.