Inactivation of Microorganisms Using Electrostatic Fields

Abstract

This research investigated whether electrostatic fields can be used to inactivate surface-borne and airborne microorganisms. Vegetative cells of Pseudomonas fluorescens and Bacillus subtilis var. niger were deposited on filters and subjected to electrostatic fields of different strengths and polarities for controlled time periods. In addition, P. fluorescens bacteria, which represent sensitive species, were aerosolized and exposed to electrostatic fields of up to +/- 10 kV/cm. The results have shown that more than 90% of the P. fluorescens cells deposited on the surface of nonconductive filters are inactivated when fields of 15 kV/cm are applied for 30 min or longer. Similar effects were observed when P. fluorescens were exposed to fields of 5 and 10 kV/cm for 2 h. In contrast, the culturability of B. subtilisvar. niger cells exposed under the same conditions did not substantially decrease. Exposure of airborne P. fluorescens to +/- 10 kV/cm for 30 s also did not result in a significant reduction of culturability. This research has shown that specific combinations of electrostatic field strength and exposure time can be used to effectively inactivate certain bacterial cells deposited on nonconductive surfaces. For the investigated conditions, the treatment was not effective for bacteria in the airborne state.

Release of Free DNA by Membrane-Impaired Bacterial Aerosols Due to Aerosolization and Air Sampling

“…This particular sampler prototype collects bioaerosols on a superhydrophobic surface and then concentrates them into small volumes of liquid (40 l or less), thus allowing one to achieve very high concentration rates (31,33). Our earlier study showed that exposure to strong electrostatic fields while airborne does not induce appreciable cell damage (60). These features of the new electrostatic precipitator-a high sample concentration rate and an ability to maintain cell integrity-should be valuable for bioaerosol detection, especially when high sensitivity and a low detection limit are desired.…”

Ilościowa i jakościowa kontrola szkodliwych czynników biologicznych w środowisku pracy

“…2002;Parker, Plaks 2004;Yao, Mainelis 2006). Wykorzystanie naturalnych właściwości elektrostatycznych cząstek powoduje, że metoda ta jest określana jako "łagodna" i wysokosprawna technika pobierania bioaerozolu (Yao, Mainelis 2005;2006).…”

Inactivation of Escherichia coli Cells in Aqueous Solution by Atmospheric-Pressure N 2 , He, Air, and O 2 Microplasmas

“…Due to the reactive species in plasma, gas-based reactive plasmas are thought to be effective in killing various microorganisms (1)(2)(3). Therefore, recently, the inactivation of microorganisms in water by atmospheric-pressure cold plasmas (APCP) has attracted great attention for biomedical and environmental applications due to their lethal effects on bacteria and fungi (4)(5)(6)(7)(8), since APCP include many reactive species similar to those in the conventional methods of microorganism inactivation, such as ozone generation (9), UV irradiation (10), chemical agents (11), electrical fields (12,13), and microwave irradiation (14).…”