Microbiological studies on the radiation environment of the ionosphere and stratosphere.
Rocket, balloon and laboratory experiments have been performed in order to study the survival chances of microorganisms, which exist under the environmental conditions of ionosphere and stratosphere. The main results are: 1. Not only near the earth, but also in the stratosphere and even in the ionosphere, microorganisms are endangered primarily by UV- and EUV-light irradiation. 2. The observed effect of more penetrating kinds of radiation was relatively unimportant. High-vacuum and temperature effects have not been observed at all. Even membrane filters and thin protein layers protected the exposed spores of Bacillus subtilis var. niger (= Bac. globigii) in a clear-cut manner. 3. UV-light with a wavelength between 200 and 300 nm reduces the number of cells able to divide much quicker, than EUV-light of the same energy level does, but damages caused by EUV-light can not be reversed by photoreactivation. 4. Microbes which have been damaged by solar radiation, can be photoreactivated to a degree. Photoreactivation is high after exposure near the Earth and significant after exposure within the stratosphere. 5. After exposure to ionospheric irradiations no changes in the antigenic behavior of E. coli cells could be detected.
Petras
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Institut fur Aerobiologie der Fraunhofer-Gesellschaft zur Forderung der angewandten Forschung e.V., Grafschaft, Federal Republic of Germany.
Bisa
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D000531:Altitude; D001272:Atmosphere; D001407:Bacillus / Q000254:growth & development / Q000528:radiation effects*; D001412:Bacillus subtilis / Q000254:growth & development / Q000528:radiation effects*; D015169:Colony Count, Microbial; D003359:Cosmic Radiation; D004926:Escherichia coli / Q000254:growth & development / Q000528:radiation effects*; D011835:Radiation Protection; D011836:Radiation Tolerance; D019445:Solar Activity; D013026:Space Flight; D014466:Ultraviolet Rays; D014893:Weightlessness