Effect of UVC Radiation on Hydrated and Desiccated Cultures of Slightly Halophilic and Non-Halophilic Methanogenic Archaea: Implications for Life on Mars.

Research paper by Navita N Sinha, Timothy A TA Kral

Indexed on: 15 May '18Published on: 15 May '18Published in: Microorganisms


Methanogens have been considered models for life on Mars for many years. In order to survive any exposure at the surface of Mars, methanogens would have to endure Martian UVC radiation. In this research, we irradiated hydrated and desiccated cultures of slightly halophilic and non-halophilic for various time intervals with UVC (254 nm) radiation. The survivability of the methanogens was determined by measuring methane concentrations in the headspace gas samples of culture tubes after re-inoculation of the methanogens into their growth-supporting media following exposure to UVC radiation. Hydrated survived 24 h of UVC exposure, while in a desiccated condition they endured for 16 h. also survived UVC radiation for 24 h in a liquid state; however, in a desiccated condition, the survivability of was only 12 h. Some of the components of the growth media could have served as shielding agents that protected cells from damage caused by exposure to ultraviolet radiation. Overall, these results suggest that limited exposure (12⁻24 h) to UVC radiation on the surface of Mars would not necessarily be a limiting factor for the survivability of and .