Hydrogen sulfide inhibits the growth of Escherichia coli through oxidative damage

Many studies have shown that hydrogen sulfide (H₂S) is both detrimental and beneficial to animals and plants, whereas its effect on bacteria is not fully understood. Here, we report that H₂S, released by sodium hydrosulfide (NaHS), significantly inhibits the growth of Escherichia coli in a dose-dependent manner. Further studies have shown that H₂S treatment stimulates the production of reactive oxygen species (ROS) and decreases glutathione (GSH) levels in E. coli, resulting in lipid peroxidation and DNA damage. H₂S also inhibits the antioxidative enzyme activities of superoxide dismutase (SOD), catalase (CAT) and glutathione reductase (GR) and induces the response of the SoxRS and OxyR regulons in E. coli. Moreover, pretreatment with the antioxidant ascorbic acid (AsA) could effectively prevent H₂S-induced toxicity in E. coli. Taken together, our results indicate that H₂S exhibits an antibacterial effect on E. coli through oxidative damage and suggest a possible application for H₂S in water and food processing.