title: Effect of ultraviolet radiation on microorganisms as a principal extremal factor of space environment.
abstract: 1. The problem of the transport of viable germs through interplanetary space has recently acquired special interest arising from the necessity of sterilization of space ships. 2. Of all cosmic extremal factors ultraviolet solar radiation is the most dangerous for microorganisms. The intensity of the most bactericidal region of ultraviolet radiation at a distance of one astronomical unit from the sun is 2 x 10(3) erg per cm2. 3. Sensitivity of microorganisms to ultraviolet rays varies in a large range. For the most resistant forms the lethal dose is approximately 440000 erg per cm2. 4. The penetrating capacity of ultraviolet radiation is very low, and therefore, even insignificant amounts of organic or mineral substances may protect the bacterial cell. 5. Dust particles of terrestrial origin carrying on themselves bacterial spores exert upon the latter a protective effect against ultraviolet radiation.
authors.affiliation: Institute of Microbiology, Academy of Sciences of the USSR, Moscow.
authors.forename: R I
authors.initials: RI
authors.lastname: Fedorova
mesh_terms: D001419:Bacteria / Q000528:radiation effects*; D019443:Cosmic Dust; D005118:Extraterrestrial Environment; D018531:Spacecraft; D013171:Spores, Bacterial / Q000528:radiation effects; D013472:Sunlight; D014466:Ultraviolet Rays
chemical_list: D019443:Cosmic Dust