title: Microorganisms of the upper layer of the atmosphere and the protective role of their cell pigments.
abstract: Of the six species of microorganisms isolated from the mesosphere, five contained pigments and were more resistant to UV radiation compared with their pigment-free mutants. The black pigment isolated from the conidia of Aspergillus niger considerably increased the UV resistance of the unpigmented mutant conidia of Penicillium notatum, the spore Circinella muscae and the vegetative cells of Micrococcus albus. From the data it is possible to conclude that in the upper layers of the Earth's atmosphere the predominant proportion of pigmented microorganisms is the consequence of natural selection by UV radiation.
authors.affiliation: Institute of Microbiology, USSR Academy of Sciences, Moscow, USSR.
authors.forename: A A
authors.initials: AA
authors.lastname: Imshenetsky
authors.forename: S V
authors.initials: SV
authors.lastname: Lysenko
authors.forename: S P
authors.initials: SP
authors.lastname: Lach
mesh_terms: D000391:Air Microbiology; D000531:Altitude; D001234:Aspergillus niger / Q000502:physiology / Q000528:radiation effects; D001272:Atmosphere; D001419:Bacteria / Q000528:radiation effects*; D018407:Bacterial Physiological Phenomena; D005658:Fungi / Q000502:physiology / Q000528:radiation effects*; D008837:Micrococcus / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D010408:Penicillium chrysogenum / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D010860:Pigments, Biological / Q000494:pharmacology / Q000502:physiology / Q000528:radiation effects*; D011836:Radiation Tolerance / Q000502:physiology*; D011837:Radiation-Protective Agents / Q000494:pharmacology; D013172:Spores, Fungal / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D010860:Pigments, Biological; D011837:Radiation-Protective Agents