Extreme environments as Mars terrestrial analogs: The Rio Tinto case

The geomicrobiological characterization of the Río Tinto (Iberian Pyritic Belt) has recently proven the importance of the iron cycle, not only in the generation of the extreme conditions of the habitat (low pH, high concentration of heavy metals), but also in the maintenance of a high level of microbial diversity. The presence of vast deposits of sulfates and iron oxides on Mars, the main products of the bioleaching of iron containing sulfides found in Río Tinto, and the physico-chemical properties of iron as a source of energy, protection from radiation and oxidative stress as well as pH control, make Río Tinto an interesting Mars terrestrial analog.