Temperature Dependence of Bacterial Inactivation by X-Rays

Abstract

Inactivation of aqueous suspensions of bacteria has been reported to be independent of the temperature of the suspension during irradiation. Lea (1) and others have reviewed the literature pertinent to this problem up to 1947. Since that time numerous reports indicate that important chemical processes occur between the initial ionization physical events and the production of the biological effect observed. Hollaender (2), Stapleton (3), and others have reviewed most of the reported investigations related to this subject. Moos (4), Goldblith et al. (5), and others have shown the importance of diffusion in reactions leading to radiation inactivation of bacteria. The findings of Bonet-Maury and Lefort (6) and Stewart and Ghormley (7) on hydrogen peroxide production in pure water systems prompted investigations in this laboratory on the relation of X-ray inactivation of bacterial suspensions to the physical state of the suspension, over the widest practicable temperature range for this organism. Concurrent with these experiments, Wood (8) investigated the effect of temperature during irradiation of the inactivation process in a haploid strain of Saccharomyces cerevisiae. Insofar as our data can be compared with those of Wood, similar results were obtained. Houtermans (9) has recently published a paper on the influence of temperature on the inactivation of E. coli. Similar data were obtained with X-rays, but the temperature effect on a-particle inactivation appeared to be very much less than on X-ray inactivation.