Radiation-induced damage in Escherichia coli B: the effect of superoxide radicals and molecular oxygen. [. gamma. irradiation of bacterial suspensions]

Journal Article · Fri Dec 01 04:00:00 EST 1978 · Radiat. Res.; (United States)

DOI:https://doi.org/10.2307/3574810· OSTI ID:6381743

Samuni, A; Czapski, G

The roles of superoxide radicals and of molecular oxygen in the radiodamage of Escherichia coli B suspended in dilute phosphate buffer were studied. The presence of high concentrations of polyethylene glycol in the ..gamma..-irradiated cell suspensions had no effect on bacterial radiosensitivity. This indicated that the damage was primarily endogenous, i.e., originated intracellularly. Saturation of the cell suspensions with N/sub 2/O doubled the radiosensitivity, thus indicating that OH radicals were responsible for the majority of the damage (indirect radiation effect). The presence of oxygen either in the absence or presence of N/sub 2/O brought about roughly a threefold increase in the radiosensitivity. Since in the presence of N/sub 2/O all e/sub aq//sup -/ were scavenged by the nitrous oxide rather than by oxygen, this shows that superoxide radicals played no role in the bacterial radiodamage. Our results substantiate the attribution of the oxygen effect to a direct interaction of O/sub 2/ with the OH-damaged sites on vital biomolecules and exclude any significant contribution of e/sub aq$/sup -/ and O/sub 2//sup -/ to the cellular radiodamage.

• Research Organization: Hebrew Univ., Jerusalem, Israel
• OSTI ID: 6381743
• Journal Information: Radiat. Res.; (United States), Journal Name: Radiat. Res.; (United States) Vol. 76:3; ISSN RAREA
• Country of Publication: United States
• Language: English

Related Subjects

560112 -- Radiation Effects on Biochemicals-- In Microorganisms-- (-1987)
560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
ALKALI METAL ISOTOPES
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
CESIUM 137
CESIUM ISOTOPES
CHALCOGENIDES
CRYOGENIC FLUIDS
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ESCHERICHIA COLI
FLUIDS
GAMMA RADIATION
HYDROXYL RADICALS
IONIZING RADIATIONS
IRRADIATION
ISOTOPES
MICROORGANISMS
NITROGEN COMPOUNDS
NITROGEN OXIDES
NITROUS OXIDE
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
OXIDES
OXYGEN
OXYGEN COMPOUNDS
RADIATION EFFECTS
RADIATIONS
RADICALS
RADIOINDUCTION
RADIOISOTOPES
RADIOSENSITIVITY
RADIOSENSITIVITY EFFECTS
SUPEROXIDE RADICALS
SUSPENSIONS
YEARS LIVING RADIOISOTOPES