INVESTIGATIONS OF EFFECT OF VACUUM AND RADIATION ON ESCHERICHIA COLI

Cells of E. coli B/r were exposed to vacuum up to 2·10-6 Torr. From these investigations it is assumed, that the damaging effect of vacuum mainly depends on the water desorption of the cells. All effects under consideration, i.e. inactivation, delay of the first cell division and increase of radiation sensitivity were obtained already in the range of about 1 Torr. They were scarcely increased by further decompression. Cells which were protected by other bacteria, nutrient media, or crystals were less damaged by vacuum. The radiation sensitivity during vacuum exposure was higher than under control conditions. In vacuum the dose resulting the same survival fraction was reduced to 1/4 for X-rays and to 1/6 for UV respectively. © 1969 Springer-Verlag.