Fig. 3
Bacteria cell structures most easily damaged by reactive oxygen species (ROS). Among the bacteria cell structures, cell envelope (cell wall and plasma membrane) as well as nucleoid are most affected by ROS-induced damages. Hydroxyl radicals (•OH) and hydrogen peroxide molecules (H2O2) have the ability to penetrate the bacteria cell envelope, whereas superoxide anion radicals (•O2 −) do not exhibit such ability