Zero-valent iron on Mars: An alternative energy source for methanogens

Zero-valent iron, montmorillonite-like smectites, and CO2 gas are known to exist on Mars, and work was performed to investigate the ability of methanogens to subsist on these materials. After 71 days of incubation at 55 °C, mean methane concentration as percent of headspace volume was 19.80 ± 1.76% (mean ± SE) for replicates containing elemental iron and 0.50 ± 0.15% for those lacking elemental iron.