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The Effect of Freezing on the Radiation Sensitivity of Bacterial Spores
Author(s) -
Matsuyama A.,
Thornley Margaret J.,
Ingram M.
Publication year - 1964
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1964.tb04819.x
Subject(s) - spore , irradiation , sterilization (economics) , chemistry , bacillus pumilus , microbiology and biotechnology , shock (circulatory) , food science , biology , bacteria , medicine , physics , genetics , nuclear physics , monetary economics , economics , foreign exchange market , foreign exchange
S ummary :Bacillus pumilus spores, irradiated under aerobic conditions, were inactivated exponentially at the same rate whether they were at room temperature (10–13°) in phosphate buffer or at ‐79° in phosphate buffer or in heart infusion broth. Clostridium welchii spores were irradiated in Robertson's cooked meat medium under anaerobic conditions. With unheated spores, and those subjected to a heat shock before irradiation, the inactivation rate was the same at room temperature and ‐79°. The same applied to spores heat shocked after irradiation for doses up to 450 Krads, but above this dose level the spores irradiated frozen were more sensitive. The effect of the heat shock, whether applied before or after irradiation, was to increase the number of survivors, and the proportionate increase appeared to vary with dose.