Role of transition metals in UV-B-induced damage to bacteria

Abstract

The purpose of this study was to explore the possible link between metals and UV-B-induced damage in bacteria. The effect of growth in the presence of enhanced concentrations of different transition metals (Co, Cu, Fe, Mn and Zn) on the UV-B sensitivity of a set of bacterial isolates was explored in terms of survival, activity and oxidative stress biomarkers (ROS generation, damage to DNA, lipid and proteins and activity of antioxidant enzymes). Metal amendment, particularly Fe, Cu and Mn, enhanced bacterial inactivation during irradiation by up to 35.8%. Amendment with Fe increased ROS generation during irradiation by 1.2-13.3%, DNA damage by 10.8-37.4% and lipid oxidative damage by 9.6-68.7%. Lipid damage during irradiation also increased after incubation with Cu and Co by up to 66.8% and 56.5% respectively. Mn amendment decreased protein carbonylation during irradiation by up to 44.2%. These results suggest a role of Fe, Co, Cu and Mn in UV-B-induced bacterial inactivation and the importance of metal homeostasis to limit the detrimental effects of ROS generated during irradiation.