Details for Ferroplasma

Ferroplasma is a chemolithotrophic relative of Thermoplasma. Like Thermoplasma, it lacks a cell wall and has an acidophilic lifestyle, but is not a thermophile, growing optimally at 35°C. Ferroplasma oxidizes Fe²⁺ to Fe³⁺ to obtain energy (this reaction generates acid) and uses CO₂ as its carbon source (autotrophy). Ferroplasma grows in mine tailings containing pyrite (FeS), its energy source (it has also been found in hydrothermally modified volcanic soils and acidic, geothermal springs). The extreme acidophily of Ferroplasma allows it to drive down the pH of its habitat to extremely low values. It is believed that after moderate acidity is generated form Fe²⁺ oxidation by organisms such as Thiobacillus ferrooxidans and Leptospirillum ferrooxidans, Ferroplasma becomes active and subsequently generates the very low pH values typical of acid mine drainage.