Exobiological Application of Spore Dosimeter in Studies Involving Solar UV Radiation
Abstract
The understanding of photobiological processes under different climates like space, early Earth, Mars and the consequences of the ozone role as a protector for the biosphere from UV solar emissions is a very important aspect in terms of the comprehension of the life evolution (Ronto et al. 2004). Consequently, recent studies have trying to understand what are the possible adaptation concepts and technologies of biological UV dosimetry, when developed for applications under climates like space and Mars surface. In this context, characteristics as a high resistance of bacterial spores to extreme conditions under extraterrestrial environments are required (Nicholson et al. 2000). A biosensor based in the spore inactivation doses (SID) of Bacillus subtilis strain TKJ6312 has been applied in the monitoring of the UV and the results compared with UV data obtained by Brewer Spectrophotometers at the INPEs Southern Space Observatory (SSO, 29.4 S, 53.8 W), South of Brazil. Due to the deficiency in both DNA repair mechanisms, Nucleotide Excision Repair (NER) and Spore Photoproduct Lyase (SP lyase), this strain is sensible to UVR and maintain the resistant for others environment conditions (Munakata et al. 2000). The biological dosimetry fulfills the criterions established by BIODOS project from the European Commission to be applied as UV-biosensor including its simplicity, facility of use and transport, long term storage and action spectrum with a good resolution (Schuch et. al. 2006). The high correlation index around 0.9 of the continuous monthly exposition of the biosensor, which began in 2000 at the SSO, when compared with BrewersUV measurements, demonstrates its application for long-term monitoring of the UV biologically-effective solar radiation. Furthermore, spores data analyses from other sites around the world agree with the UV seasonal variation data cited by the literature in terms of different and adverse environmental conditions from equatorial to higher latitudes sites (Munakata et. al. 2006). Considering the expectations of international exobiology groups to study the spatial solar radiation under different planetary environments using biological systems the application of the Bacillus subtilis TKJ 6312 seems to be a very nice biosensor tool.
- Publication:
-
Origins of Life and Evolution of the Biosphere
- Pub Date:
- May 2009
- DOI:
- 10.1007/s11084-009-9164-7
- Bibcode:
- 2009OLEB...39..373R