Generation of reactive oxygen species and oxidative stress in Escherichia coli and Staphylococcus aureus by a novel semiconductor catalyst
- 390 Downloads
The objective of this study was to investigate antimicrobial mechanisms of a new catalytic material (charge transfer auto oxidation–reduction type catalyst, CT catalyst) that may have great potential for application in water/wastewater treatment. Generation of reactive oxygen species (ROS) in bacteria-free solution, induction of ROS and oxidative damage in bacteria (including E. coli and S. aureus) were examined for the CT catalyst. The results showed that significantly higher (p < 0.05, via t-test) amount of hydroxyl radicals was generated by the CT catalyst compared with the control, particularly after 6 h of contact time that more than twice of the amount of the control was produced. The generation of ROS in the bacteria was greater under higher pH and temperature levels, which closely related with the oxidative damage in cells. The results indicated that CT catalyst induced oxidative damage in the bacteria might serve as an important mechanism interpreting the anti-microbial function of the CT catalyst.
KeywordsSuperoxide anions Hydroxyl radicals Lipid peroxidation Protein oxidation Antibacterial activity Charge transfer auto oxidation–reduction type catalyst
Financial support from the Faculty Research Grant, Hong Kong Baptist University (No. FRG/08-09/II-34) is gratefully acknowledged.
- Farr SB, Kogoma T (1991) Oxidative stress responses in Escherichia coli and Salmonella typhimurium. Microbiol Mol Biol Rev 55:561–585Google Scholar
- Ichimura S, Ichimura K (2001) Charge transfer auto-oxidation-reduction semiconductor catalyst: application to MINOYAKI tiles and it’s effects. Trans Mater Res Soc Jpn 26:1045–1048Google Scholar
- Meier B, Parak F, Desideri A, Rotilio G (1997) Comparative stability studies on the iron and manganese forms of the cambialistic superoxide dismutase from Propionibacterium shermanii. Fed Eur Biochem Soc 414:122–124Google Scholar
- Yagi K (1998) Simple assay for the level of total lipid peroxides in serum or plasma. In: Armstrong D (ed) Free radicals and antioxidant protocols. Humana Press, Totowa, pp 101–106Google Scholar