Survival of Microorganisms under the Extreme Conditions of the Atacama Desert

摘要: Spores of Bacillus subtilis, conidia Aspergillus niger, versicolor and ochraceus andcells Deinococcus radiodurans have been exposed in the dark at two locations (at about 23°S 24°S) Atacama Desert for up to 15 months. B. subtilis spores (survival ∼15%) A. niger ∼30%) outlived other species. The survival conidiaand species was only slightly poorer than that thecorresponding laboratory controls. However, cells did not survive desertexposure, because they are readily inactivated relativehumidities between 40 80% which typically occurduring desert nights. Cellular monolayers dry sporesand addition full sunlight several hours. solar fluences causing 63% loss viability (F37-values) determined.These F37-values compared with those determined atother global such as Punta Arenas (53°S), Key Largo (25°N) or Mainz (50°N) during same season. Thesolar UVB radiation kills even most resistantmicroorganisms within a few hours due DNA damages. Thedata also discussed respect possible similaritiesbetween climatic conditions recent Desertand deserts early Mars.