An archaeal iron-oxidizing extreme acidophile important in acid mine drainage

A new species of Archaea grows at pH similar to 0.5 and similar to 40 degre es C in slime streamers and attached to pyrite surfaces at a sulfide ore bo dy, Iron Mountain, California. This iron-oxidizing Archaeon is capable of g rowth at pH 0. This species represents a dominant prokaryote in the environ ment studied (slimes and sediments) and constituted up to 85% of the microb ial community when solution concentrations were high (conductivity of 100 t o 160 millisiemens per centimeter). The presence of this and other closely related Thermoplasmales suggests that these acidophiles are important contr ibutors to acid mine drainage and may substantially impact iron and sulfur cycles.