Biomining metals from pyritic ores: physiological, biochemical, and biophysical considerations

Microorganisms and their enzymes drive global biogeochemical cycles and impact ecosystem processes that directly influence plant, animal, and environmental health. Key reactions are catalyzed by metalloenzymes with active sites that contain iron (Fe), nickel (Ni), cobalt (Co), and molybdenum (Mo) sulfide cofactors. However, under anoxic conditions, such metals are bio-unavailable, raising questions of how anaerobes biosynthesize such metalloenzymes. Recent work indicates that methanogens can convert pyrite (FeS2), the most abundant iron sulfide mineral in Earth's crust, into metalloenzymes that interconvert CO2 to CH4, N2 to NH3, and H2 to H+.