0459862 - ÚFP 2017 RIV GB eng J - Journal Article
Doležalová, Eva - Prukner, Václav - Lukeš, Petr - Šimek, Milan
Stress response of Escherichia coli induced by surface streamer discharge in humid air.
Journal of Physics D-Applied Physics. Roč. 49, č. 7 (2016), s. 075401. ISSN 0022-3727. E-ISSN 1361-6463
R&D Projects: GA MŠMT(CZ) LD13010; GA MŠMT(CZ) LD14080
Grant - others:European Cooperation in Science and Technology(XE) COST MP1101
Program: Materials, Physical and Nanosciences COST Action MP1101
Institutional support: RVO:61389021
Keywords : bacterial activity * culturability * dielectric barrier discharges (DBD) * lipid peroxidation * stress
Subject RIV: BL - Plasma and Gas Discharge Physics
Impact factor: 2.588, year: 2016
http://iopscience.iop.org/article/10.1088/0022-3727/49/7/075401/meta

Inactivation of Escherichia coli by means of surface streamer discharge has been investigated to obtain new insights into the key mechanisms involved, with a particular emphasis placed on the microbial response to plasma-induced stress. The surface streamer discharge was produced in coplanar dielectric barrier discharge electrode geometry, and was driven by an amplitude-modulated ac high voltage in humid synthetic air at atmospheric pressure. The response to plasma-induced stress was evaluated by using conventional cultivation, sublethal injury and resazurin assay and the LIVE/DEAD (R) BacLight (TM) Bacterial Viability kit. Compared to conventional cultivation, the LIVE/DEAD (R) test labels bacteria with damaged membranes, while resazurin assay tracks their metabolic activity. Our results clearly demonstrate that the treated bacteria partly lost their ability to grow properly, i.e. they became injured and culturable, or even viable but nonculturable (VBNC). The ability to develop colonies could have been lost due to damage of the bacterial membrane. Damage of the membranes was mainly caused by the lipid peroxidation, evidencing the key role of oxygen reactive species, in particular ozone. We conclude that the conventional cultivation method overestimates the decontamination efficiency of various plasma sources, and must therefore be complemented by alternative techniques capable of resolving viable but nonculturable bacteria.
Permanent Link: http://hdl.handle.net/11104/0260025