Identifying the mediators of intracellular E. coli inactivation under UVA light: The (photo) Fenton process and singlet oxygen.

ABSTRACT: Solar disinfection (SODIS) was probed for its underlying mechanism. When Escherichia coli was exposed to UVA irradiation, the dominant solar fraction acting in SODIS process, cells exhibited a shoulder before death ensued. This profile resembles cell killing by hydrogen peroxide (H₂O₂). Indeed, the use of specialized strains revealed that UVA exposure triggers intracellular H₂O₂ formation. The resultant H₂O₂ stress was especially impactful because UVA also inactivated the processes that degrade H₂O₂-peroxidases through the suppression of metabolism, and catalases through direct enzyme damage. Cell killing was enhanced when water was replaced with D₂O, suggesting that singlet oxygen plays a ro

SUBMITTER: Giannakis S 

PROVIDER: S-EPMC11136163 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature