title: Wavelength dependence of biological damage induced by UV radiation on bacteria.
abstract: The biological effects of UV radiation of different wavelengths (UVA, UVB and UVC) were assessed in nine bacterial isolates displaying different UV sensitivities. Biological effects (survival and activity) and molecular markers of oxidative stress [DNA strand breakage (DSB), generation of reactive oxygen species (ROS), oxidative damage to proteins and lipids, and the activity of antioxidant enzymes catalase and superoxide dismutase] were quantified and statistically analyzed in order to identify the major determinants of cell inactivation under the different spectral regions. Survival and activity followed a clear wavelength dependence, being highest under UVA and lowest under UVC. The generation of ROS, as well as protein and lipid oxidation, followed the same pattern. DNA damage (DSB) showed the inverse trend. Multiple stepwise regression analysis revealed that survival under UVA, UVB and UVC wavelengths was best explained by DSB, oxidative damage to lipids, and intracellular ROS levels, respectively.
authors.affiliation: Department of Biology & CESAM, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: Ana L
authors.initials: AL
authors.lastname: Santos
authors.forename: Vanessa
authors.initials: V
authors.lastname: Oliveira
authors.forename: Inês
authors.initials: I
authors.lastname: Baptista
authors.forename: Isabel
authors.initials: I
authors.lastname: Henriques
authors.forename: Newton C M
authors.initials: NC
authors.lastname: Gomes
authors.forename: Adelaide
authors.initials: A
authors.lastname: Almeida
authors.forename: António
authors.initials: A
authors.lastname: Correia
authors.forename: Ângela
authors.initials: Â
authors.lastname: Cunha
mesh_terms: D001419:Bacteria / Q000201:enzymology / Q000235:genetics / Q000528:radiation effects*; D002374:Catalase / Q000378:metabolism; D004249:DNA Damage / Q000528:radiation effects*; D008055:Lipids / Q000528:radiation effects; D050296:Microbial Viability / Q000528:radiation effects; D018384:Oxidative Stress / Q000528:radiation effects; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D008055:Lipids; D017382:Reactive Oxygen Species; D002374:Catalase; D013482:Superoxide Dismutase