Abstract
Inadequately aerated Escherichia coli B/r cultures did not shut their respiration off 60 min after ultraviolet light (52 M/m2 at 254 nm) as they did when well supplied with oxygen. Since cessation of respiaration is associated with cell death, the result suggested that oxygen toxicity by superoxide radicals generated by cell metabolism might be responsible for cell death. The specific activity of superoxide dismutase, which scavenges O2- radicals, increased twofold after 90 min of adequate aeration, but the specific activity of catalase remained constant. Respiration and viability of irradiated cells were affected not at all by the presence of superoxide dismutase and only slightly by the presence of catalase. Metal ions such as Mn2+ and Fe2+ inducers of superoxide dismutase, had no effect on respiration and viability. When irradiated cells were incubated under N2 for 90 min, the respiration, growth, and viability time-course responses were the same as for the cells not exposed to anareobiosis. We conclude that superoxide anions generated at the time of irradiation play no part in cessation delays the ultraviolet light-induced synthesis of proteins responsible for the irreversible cessation of respiration.
Full text
PDF
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BEERS R. F., Jr, SIZER I. W. A spectrophotometric method for measuring the breakdown of hydrogen peroxide by catalase. J Biol Chem. 1952 Mar;195(1):133–140. [PubMed] [Google Scholar]
- Fridovich I. Superoxide dismutases. Adv Enzymol Relat Areas Mol Biol. 1974;41(0):35–97. doi: 10.1002/9780470122860.ch2. [DOI] [PubMed] [Google Scholar]
- Fridovich I. Superoxide dismutases. Annu Rev Biochem. 1975;44:147–159. doi: 10.1146/annurev.bi.44.070175.001051. [DOI] [PubMed] [Google Scholar]
- Gregory E. M., Fridovich I. Induction of superoxide dismutase by molecular oxygen. J Bacteriol. 1973 May;114(2):543–548. doi: 10.1128/jb.114.2.543-548.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gregory E. M., Yost F. J., Jr, Fridovich I. Superoxide dismutases of Escherichia coli: intracellular localization and functions. J Bacteriol. 1973 Sep;115(3):987–991. doi: 10.1128/jb.115.3.987-991.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LATARJET R., CALDAS L. R., MILETIC B., MORENNE P. Chemical restoration in irradiated micro-organisms. Br J Radiol. 1954 Jan;27(313):54–56. doi: 10.1259/0007-1285-27-313-54. [DOI] [PubMed] [Google Scholar]
- Marklund S., Marklund G. Involvement of the superoxide anion radical in the autoxidation of pyrogallol and a convenient assay for superoxide dismutase. Eur J Biochem. 1974 Sep 16;47(3):469–474. doi: 10.1111/j.1432-1033.1974.tb03714.x. [DOI] [PubMed] [Google Scholar]
- Schenley R. L., Fisher W. D., Swenson P. A., Khachatourians G. G. Centrifugal separation of irradiated cultures of Escherichia coli cells into viable and nonviable populations. J Bacteriol. 1976 May;126(2):977–984. doi: 10.1128/jb.126.2.977-984.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Swenson P. A., Schenley R. L. Evidence for the control of respiration by DNA in ultraviolet-irradiated Escherichia coli B-r cells. Mutat Res. 1970 May;9(5):443–453. doi: 10.1016/0027-5107(70)90028-x. [DOI] [PubMed] [Google Scholar]
- Swenson P. A., Schenley R. L. Evidence relating cessation of respiration, cell envelope changes, and death in ultraviolet-irradiated Escherichia coli B-r cells. J Bacteriol. 1974 Feb;117(2):551–559. doi: 10.1128/jb.117.2.551-559.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TORRIANI A. M., JOLIT M. Sur la réactivation de bactéries stérilisées par le rayonnement UV. C R Hebd Seances Acad Sci. 1949 Sep 12;229(11):557–559. [PubMed] [Google Scholar]