Survival of lichens and bacteria exposed to outer space conditions – Results of the Lithopanspermia experiments

Effects of UVC254 nm on the photosynthetic activity of photobionts from the astrobiologically relevant lichens Buellia frigida and Circinaria gyrosa

“…Compared to the high viability and photosynthetic activity rates of photobionts in former simulation, space and Mars exposure experiments (de la Torre et al , 2010; de Vera et al 2008Raggio et al 2011;Onofri et al 2012;Sánchez et al 2012Sánchez et al , 2014Brandt et al 2014) the present study reveals a strong decrease of the photosynthetic capacities in both investigated photobionts. To explain this, the differences between former and recent studies should be addressed: while the photobionts of the present studies were exposed to UVC as isolated cultivars under constantly wet (i.e.…”

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In the past decade, various astrobiological studies on different lichen species investigated the impairment of viability and photosynthetic activity by exposure to simulated or real space parameters (as vacuum, polychromatic ultraviolet (UV)-radiation and monochromatic UVC) and consistently found high post-exposure viability as well as low rates of photosynthetic impairment (de Vera et al 2003(de Vera et al , 2004a2004b;de la Torre et al 2010;Onofri et al 2012;Sánchez et al 2012Sánchez et al , 2014Brandt et al 2014). To achieve a better understanding of the basic mechanisms of resistance, the present study subdued isolated and metabolically active photobionts of two astrobiologically relevant lichens to UVC 254 nm , examined its effect on photosynthetic activity by chlorophyll a fluorescence and characterized the UVC-induced damages by quantum yield reduction and measurements of non-photochemical quenching.

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Earth as a Tool for Astrobiology—A European Perspective

“…Eukaryotes (e.g. lichens, microcolonial fungi and tardigrades) have also been studied, and shown a high resistance against the extreme conditions Jänchen et al 2015, Onofri et al 2004, 2012, Sancho et al 2007, de la Torre et al 2010, 2014b. In addition, fossil traces of primitive prokaryotes in well-preserved rocks from the early Earth constitute ideal analogues for potential primitive life forms on the early Mars (Westall et al 2015a(Westall et al , 2015b.…”

Fluorescent minerals – A potential source of UV protection and visible light for the growth of green algae and cyanobacteria in extreme cosmic environments

“…Another study tested the survivability of both lichens and cyanobacteria in space conditions while exposed for ten days on the Biopan facility of the European Space Agency (ESA), lichens were found to be more resistant to space conditions than bacteria (De la Torre et al, 2010). It must be noted however that all of these previous studies involved testing the survivability of dried microbial cells against UV among other factors in space, this study however differs in that it uses microbial aliquots, not dried cells.…”