Bacterial inactivation in water, DNA strand breaking, and membrane damage induced by ultraviolet-assisted titanium dioxide photocatalysis

Soohyun Kim, Kashif Ghafoor, Jooyoung Lee, Mei Feng, Jungyeon Hong, Dong Un Lee, Jiyong Park

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

The effects of UV-assisted TiO2-photocatalytic oxidation (PCO) inactivation of pathogenic bacteria (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella typhimurium) in a liquid culture using different domains of UV irradiation (A, B and C) were evaluated. Structural changes in super-coiled plasmid DNA (pUC19) and genomic DNA of E. coli were observed using gel electrophoresis to demonstrate the photodynamic DNA strand breaking activity of UV-assisted TiO2-PCO. Membrane damage in bacterial cells was observed using both a scanning electron microscope (SEM) and a confocal laser scanning microscope (CLSM). Both UVC-TiO2-PCO and UVC alone resulted in an earlier bactericidal phase (initial counts of approximately 6 log CFU/mL) in 60s and 90s, respectively, in liquid culture. UVC-TiO2-PCO treatment for 6min converted all plasmid DNA to the linear form; however, under UVC irradiation alone, super-coiled DNA remained. Prolonged UVC-TiO2-PCO treatment resulted in structural changes in genomic DNA from E. coli. SEM observations revealed that bacteria suffered severe visible cell damage after UVC-TiO2-PCO treatment for 30-60min. S. typhimurium cells showed visible damage after 30min, which was confirmed using CLSM. All treated cells were stained red using propidium iodide under a fluorescent light.

Original languageEnglish
Pages (from-to)4403-4411
Number of pages9
JournalWater Research
Volume47
Issue number13
DOIs
Publication statusPublished - 2013 Sep 1

All Science Journal Classification (ASJC) codes

  • Ecological Modelling
  • Water Science and Technology
  • Waste Management and Disposal
  • Pollution

Fingerprint Dive into the research topics of 'Bacterial inactivation in water, DNA strand breaking, and membrane damage induced by ultraviolet-assisted titanium dioxide photocatalysis'. Together they form a unique fingerprint.

  • Cite this