Perchlorates on Mars enhance the bacteriocidal effects of UV light
Jennifer Wadsworth & Charles S. Cockell
Scientific Reports 7, Article number: 4662 (2017)
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Received: 15 February 2017 Accepted: 22 May 2017
Published online: 06 July 2017
Source/Fonte: NASA
Abstract
Perchlorates have been identified on the surface of Mars. This has prompted speculation of what their influence would be on habitability. We show that when irradiated with a simulated Martian UV flux, perchlorates become bacteriocidal. At concentrations associated with Martian surface regolith, vegetative cells of Bacillus subtilis in Martian analogue environments lost viability within minutes. Two other components of the Martian surface, iron oxides and hydrogen peroxide, act in synergy with irradiated perchlorates to cause a 10.8-fold increase in cell death when compared to cells exposed to UV radiation after 60 seconds of exposure. These data show that the combined effects of at least three components of the Martian surface, activated by surface photochemistry, render the present-day surface more uninhabitable than previously thought, and demonstrate the low probability of survival of biological contaminants released from robotic and human exploration missions.
Acknowledgements
We acknowledge support from the UK Space Agency for this work under the Aurora program and support for the PhD funding for J. Wadsworth. Support was also provided by Science and Technology Facilities Council (STFC) Grant no. ST/M001261/1.
Author information
Affiliations
UK Centre for Astrobiology, School of Physics and Astronomy, University of Edinburgh, Edinburgh, EH10 4EP, UK
Jennifer Wadsworth & Charles S. Cockell
Contributions
C.S.C. & J.W. designed the project; J.W. performed the research and wrote the manuscript.
Competing Interests
The authors declare that they have no competing interests.
Corresponding author
Correspondence to Jennifer Wadsworth.
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