Sensitivity of Deinococcus radiodurans to γ-Irradiation: A Novel Approach by Fourier Transform Infrared Spectroscopy

• Published in: Archives of biochemistry and biophysics 2001-10, Vol.394 (2), p.265-274
• Main Authors: Melin, Anne-Marie, Perromat, Annie, Déléris, Gérard
• Format: Article
• Language: English
• Subjects: Algorithms; Cluster Analysis; Deinococcus radiodurans; Dose-Response Relationship, Radiation; FT-IR; Gamma Rays; ionizing radiations; Micrococcus - growth & development; Micrococcus - radiation effects; nucleic acids; Oxidative Stress; Spectroscopy, Fourier Transform Infrared - methods
• ISSN: 0003-9861; 1096-0384
• DOI: 10.1006/abbi.2001.2533

Deinococcus radiodurans is a red-pigmented coccus known to be particularly resistant to both chemical and radiative agents. Fourier transform infrared (FT-IR) spectroscopy was used as a convenient and easy-to-run method to monitor damage induced in this bacterium by ionizing radiations. First, stationary-phase cultures were submitted to increasing doses of γ-irradiation (137Cs source). Beyond a threshold of 11 kGy, striking changes occurred in spectra of irradiated samples compared with unirradiated ones, especially in the 1750–900 cm−1 region, which is spectroscopically assigned to amide I and II components, nucleotide bases, the phosphodiester backbone, and the sugar ring. Second, bacterial cultures were postirradiation reincubated. After a reincubation time of 15 h, the oxidative stress was in part overwhelmed, and the growth of D. radiodurans again occurred, although some biocellular components remained altered. Consequently, FT-IR analysis is an accurate means to rapidly visualize biomolecular changes undergone by cells both after γ-irradiation and during the repair mechanism.