| Comments |
P.13 5th paragraph: "Table 1.2 shows several examples of microorganisms, which survived exposure to extreme physicochemical factors. The time of exposure varied greatly, for example,
Deinococcus radiodurans will, depending on the source of gamma radiation, survive a dose of about 20,000 Gy [Gray], obtained by a pulse lasting a few hours (primary source Ito et al. 1983). These levels of radiation are not found naturally on present-day Earth. Several more species of Deinococcus are known, which possess high resistance against radiation and desiccation, and several genomes have been sequenced (see Heulin et al. 2017, this volume). Interestingly, irradiation at a temperature of −79 °C – simulating Martian surface conditions – increased the resistance of Deinococcus radiodurans markedly, compared to irradiation at room temperature or on ice (Dartnell et al. 2010)." |