Biomining is the technique of extracting metals from ores and other solid materials typically using micro-organisms (bacteria, archae, fungi or plants).

It was discovered in the mid-1900s that some microorganisms can use metals to support their energy needs. In addition, certain microbes excrete compounds that break down the metal-containing chemical complexes in ores. As a result, they are capable of separating metals from ores, providing a soluble form of metals which can then be isolated.  This includes stable metals such as iron, copper, zinc and gold as well as unstable atoms such as uranium and thorium. Companies can now grow large-scale cultures in chemostats to separate metals, which can then be converted into many marketable metal compounds.

Compared to typical mining that uses hazardous chemicals and has a large CO2 footprint, biomining represents an environmentally friendly alternative, producing very little (if at all) hazardous waste. The same concept can be used for bioremediation models. Bacteria can be inoculated into environments contaminated with metals, oils, or other toxic compounds. The bacteria clean the environment by absorbing toxic compounds through a variety of methods. Therefore, the multitude of solutions employed by bacterial biochemistry can be used mine for metals and clean industrial waste streams, extracting critical raw materials in process.

In fact, biomining is so versatile that it can be used on other planetary bodies. Studies on the international space station have shown microorganisms from extreme environments on Earth can leach a large variety of important minerals and metals from rocks when exposed to the cold, heat, radiation and vacuum of space.