Evaluation of the Resistance of Chroococcidiopsis spp. to Sparsely and Densely Ionizing Irradiation.
Studying the resistance of cyanobacteria to ionizing radiation provides relevant information regarding astrobiology-related topics including the search for life on Mars, lithopanspermia, and biological life-support systems. Here, we report on the resistance of desert cyanobacteria of the genus Chroococcidiopsis, which were exposed (as part of the STARLIFE series of experiments) in both hydrated and dried states to ionizing radiation with different linear energy transfer values (0.2 to 200 keV/μm). Irradiation with up to 1 kGy of He or Si ions, 2 kGy of Fe ions, 5 kGy of X-rays, or 11.59 kGy of γ rays (60Co) did not eradicate Chroococcidiopsis populations, nor did it induce detectable damage to DNA or plasma membranes. The relevance of these results for astrobiology is briefly discussed. Key Words: Ionizing radiation-Linear energy transfer-Lithopanspermia-Cyanobacterial radioresistance-Chroococcidiopsis-Mars. Astrobiology 17, 118-125.
1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy .
Cyprien
C
Verseux
1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy .|2 Astrobiological Laboratories Research Group, Institute of Planetary Research , Management and Infrastructure, German Aerospace Center (DLR), Berlin, Germany .
Mickael
M
Baqué
1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy .
Riccardo
R
Cifariello
1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy .
Claudia
C
Fagliarone
3 Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine , German Aerospace Center (DLR), Cologne, Germany .
Marina
M
Raguse
3 Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine , German Aerospace Center (DLR), Cologne, Germany .
Ralf
R
Moeller
1 Department of Biology, Laboratory of Astrobiology and Molecular Biology of Cyanobacteria from Extreme Environments, University of Rome Tor Vergata , Rome, Italy .
Daniela
D
Billi
D002462:Cell Membrane / Q000528:radiation effects; D000458:Cyanobacteria / Q000235:genetics / Q000528:radiation effects*; D004249:DNA Damage; D004269:DNA, Bacterial / Q000235:genetics; D003890:Desiccation; D016680:Genome, Bacterial; D050296:Microbial Viability / Q000528:radiation effects; D016133:Polymerase Chain Reaction; D011836:Radiation Tolerance / Q000528:radiation effects*; D011839:Radiation, Ionizing; D019105:Random Amplified Polymorphic DNA Technique; D014965:X-Rays
D004269:DNA, Bacterial