“…More recently, however, evidence has been mounting that other factors such as high intracellular manganese concentrations and protection of proteins from oxidation (Daly et al, 2004;Ghosal et al, 2005;Daly, 2009) are key determinants of D. radiodurans' radiation survival. Due to this extreme radioresistance, as well as resilience to desiccation, hydrogen peroxide, and UV radiation, D. radiodurans is commonly used as a model strain for microorganisms able to survive on the martian surface (e.g., Richmond et al, 1999;Horneck, 2000;Pavlov et al, 2002;Dartnell et al, 2007a;de La Vega et al, 2007). More recently, strains of a hyperthermophilic archaeon Thermococcus, isolated from a submarine hydrothermal vent environment, have been found with a radiation resistance approaching that of D. radiodurans ( Jolivet et al, 2003( Jolivet et al, , 2004.…”