The PUR Experiment on the EXPOSE-R facility: biological dosimetry of solar extraterrestrial UV radiation

Abstract

The aim of our experiment Phage and Uracil Response was to extend the use of bacteriophage T7 and uracil biological dosimeters for measuring the biologically effective ultraviolet (UV) dose in the harsh extraterrestrial radiation conditions. The biological detectors were exposed in vacuum-tightly cases in the European Space Agency (ESA) astrobiological exposure facility attached to the external platform of Zvezda (EXPOSE-R). EXPOSE-R took off to the International Space Station (ISS) in November 2008 and was installed on the External platform of the Russian module Zvezda of the ISS in March 2009. Our goal was to determine the dose-effect relation for the formation of photoproducts (i.e. damage to phage DNA and uracil, respectively). The extraterrestrial solar UV radiation ranges over the whole spectrum from vacuum-UV (λ < 200 nm) to UVA (315 nm < λ < 400 nm), which causes photolesions (photoproducts) in the nucleic acids/their components either by photoionization or excitation. However, these wavelengths cause not only photolesions but in a wavelength-dependent efficiency the reversion of some photolesions, too. Our biological detectors measured in situ conditions the resultant of both reactions induced by the extraterrestrial UV radiation. From this aspect the role of the photoreversion in the extension of the biological UV dosimetry are discussed.

Astrovirology: Viruses at Large in the Universe

“…Poliovirus and bacteriophage T1 were exposed to the space environment on high-altitude balloons and rockets for short times without significant loss of activity (Parvenov and Lukin, 1973). Dried bacteriophage T7 was used as a biological dosimeter for UV irradiation on the International Space Station (ISS), but infectivity was not tested thereafter (Be ´rces et al, 2015). A survey of virion stability studies was published (Griffin, 2013), but none of these studies addresses possible survival of viruses to interplanetary transit.…”

The astrobiological mission EXPOSE-R on board of the International Space Station

“…The obtained results from EXPOSE-R, one of the longest international astrobiological exposure missions in LEO are collected in this issue (Berger et al 2014;Bertrand et al 2014;Bérces et al 2014;Bryce et al 2014;Bryson et al 2014;Carrasco et al 2014;Cottin et al 2014;Dachev et al 2014;Mancinelli et al 2014;Neuberger et al 2014;Novikova et al 2014;Panitz et al 2014;Vergne et al 2014).…”

“…Study of the probabilities and limitations for life to be distributed among the bodies of our Solar System. After peer review of the submitted proposals, six experiments of the ROSE consortium were selected for flight (Table 1) (Bérces et al 2014;Bryce et al 2014;Mancinelli et al 2014;Neuberger et al 2014;Panitz et al 2014). This set of biological experiments was later expanded by a Russian experiment provided by the IBMP in Moscow, IBMP and by SEEDS as part of the chemical experiment AMINO.…”

“…Here, we present the technical and operational details of the EXPOSE-R mission. Results of the experiments participating in the EXPOSE-R mission are reported by the experimenters individually in this issue (Bérces et al 2014; Berger et al 2014; Bertrand et al 2014; Bryce et al 2014; Bryson et al 2014; Carrasco et al 2014; Cottin et al 2014; Dachev et al 2014; Mancinelli et al 2014; Neuberger et al 2014; Novikova et al 2014; Panitz et al . 2014; Vergne et al 2014).…”

Microbial Pathogenicity in Space

“…Only a few studies have looked into virus stability in the context of space exploration, tested with exposure to simulated space-like conditions, high-altitude balloons and rocket launches, or on-board experiments at the ISS. Tested viruses include e.g., bacteriophages T1 and T7, the tobacco mosaic virus, and poliovirus with minimal infectivity losses [ 94 , 95 , 96 ]. It is worth noting that viruses are the only known biological entities with a “phoenix phenotype”: infection of multiple damaged viruses can restore replication capability if they have an equivalent to a full, undamaged genome [ 93 ].…”