Abstract
Spores of Clostridium botulinum 33A exhibit a sigmoidal survival curve if subjected to gamma radiation. The present investigation was concerned with two questions: (i) what is the form of an ultraviolet (UV)-survival curve and (ii) what is the combined effect of UV- and gamma radiation? The UV-survival curve was found to be of sigmoidal type with a “shoulder” width of 675 ergs/mm2 and a D10 (exp) of 2,950 ergs/mm2. To test the combination effect, spores were subjected to UV doses of 225, 450, 675, and 900 ergs/mm2 followed by a series of increasing doses of gamma rays from 200 to 2,000 krad in 200-krad steps. The gamma ray-survival curves showed that increasing UV pretreatment caused a gradual loss of the “Prodiginine” yielding straight line exponential survival curves after preirradiation with UV doses of 675 ergs/mm2 and above. Simultaneously the D10 value for gamma-ray irradiation was reduced, e.g. UV preirradiation with 900 ergs/mm2 reduced the D10 by 40%. This observation emphasizes the potential practical advantage of combining UV and gamma rays for sterilization of heat-sensitive commodities.
Full text
PDF






Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- ANELLIS A., GRECZ N., BERKOWITZ D. SURVIVAL OF CLOSTRIDIUM BOTULINUM SPORES. Appl Microbiol. 1965 May;13:397–401. doi: 10.1128/am.13.3.397-401.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- EMMERSON P. T., HOWARD-FLANDERS P. POST-IRRADIATION DEGRADATION OF DNA FOLLOWING EXPOSURE OF UV-SENSITIVE AND RESISTANT BACTERIA TO X-RAYS. Biochem Biophys Res Commun. 1965 Jan 4;18:24–29. doi: 10.1016/0006-291x(65)90876-4. [DOI] [PubMed] [Google Scholar]
- Ginoza W. The effects of ionizing radiation on nucleic acids of bacteriophages and bacterial cells. Annu Rev Microbiol. 1967;21:325–368. doi: 10.1146/annurev.mi.21.100167.001545. [DOI] [PubMed] [Google Scholar]
- KOS E., DRAKULIC M. Effect of some metabolites and antimetabolites on the breakdown of deoxyribonucleic acid and on the colony-forming ability of Escherichia coli B after gamma irradiation II. Effect of phosphorylated derivatives of adenosine and pyrophosphate. Radiat Res. 1963 Jul;19:439–446. [PubMed] [Google Scholar]
- MOSELEY B. E., LASER H. REPAIR OF X-RAY IN MICROCOCCUS RADIODURANS. Proc R Soc Lond B Biol Sci. 1965 Apr 13;162:210–222. doi: 10.1098/rspb.1965.0035. [DOI] [PubMed] [Google Scholar]
- Moseley B. E., Laser H. Similarity of repair of ionizing and ultra-violet radiation damage in Micrococcus radiodurans. Nature. 1965 Apr 24;206(982):373–375. doi: 10.1038/206373a0. [DOI] [PubMed] [Google Scholar]
- SETLOW R. B., SETLOW J. K. Evidence that ultraviolet-induced thymine dimers in DNA cause biological damage. Proc Natl Acad Sci U S A. 1962 Jul 15;48:1250–1257. doi: 10.1073/pnas.48.7.1250. [DOI] [PMC free article] [PubMed] [Google Scholar]
- STUY J. H. Studies on the radiation inactivation of microorganisms. VI. X-ray induced breakdown of deoxyribonucleic acid in Haemophilus influenzae and in other bacteria. J Bacteriol. 1960 May;79:707–715. doi: 10.1128/jb.79.5.707-715.1960. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Szybalski W. Molecular events resulting in radiation injury, repair and sensitization of DNA. Radiat Res Suppl. 1967;7:147–159. [PubMed] [Google Scholar]
- TYLER S. A., DIPERT M. H. On estimating the constants of the 'multi-hit' curve using a medium speed digital computer. Phys Med Biol. 1962 Oct;7:201–212. doi: 10.1088/0031-9155/7/2/306. [DOI] [PubMed] [Google Scholar]