A morphological study of the changes in the ultrastructure of a bacterial biofilm disrupted by an ac corona discharge in air

Abstract

The morphology of bacterial cells and biofilms subjected to a low frequency (∼105 Hz) ac (∼10−1 A) corona discharge was investigated using electron microscopy. A low-frequency ac corona discharge in air is shown to have a bactericidal and bacteriostatic effect on Escherichia coli M17 culture at both the cellular and population levels. Corona exposure inhibits the formation of a microbial community and results in the destruction of formed biofilms. This paper presents data on changes in the ultrastructure of cells and biofilms after corona treatment. Our results suggest that the E. coli M17 cells inside biofilms are affected with results similar to sub-lethal and lethal thermal exposure. Some of the biological aspects of colony and biofilm cells death are evaluated. Morphological changes in the ultrastructure of the biofilms under corona treatment are described. Our results indicate that the heating effect is the main factor responsible for the corona-induced inactivation of bacteria.

Sterilization of sealed PVDF pouches containing decellularized scaffold by electrical stimulation

“…[ 23,24 ] As a direct mechanism ES mediates microbial death by disrupting the integrity of the microbial membrane or through electrolysis of molecules on the bacterial cell. [ 25–27 ] Thus, to determine sterilization mechanisms, we observed the membranes of the microorganisms using SEM. ES inactivated S. aureus by destroying its membrane, as observed in the morphology of dead organisms.…”

“…[ 23,24,36 ] The direct mechanism involves ES‐mediated microbial death caused by disruption of the integrity of microbial membranes or electrolysis of molecules on the bacterial cell surface. [ 25–27 ] In contrast, indirect mechanisms inactivates microorganisms by pH and temperature changes or electrolysis products. The sterilization effects of pH and temperature are not the major causes, because they are a temporary phenomenon in aqueous solutions during ES treatment.…”

Feasibility of C 3 F 7 CN/CO 2 gas mixtures in high‐voltage DC GIL: a review on recent advances

“…PD is another important concern in engineering application of C 3 F 7 CN gas mixture [30]. The presence of insulation defects, especially moving particle and protrusions would result in PD.…”

Experimental study on the partial discharge and AC breakdown properties of C 4 F 7 N/CO 2 mixture

“…Moreover, partial discharge (PD) behaviour is another important concern for engineering application of C 4 F 7 N gas mixture [14]. The various kinds of insulation defects produced in the long‐term operation of gas insulated equipment will cause PD.…”

“…4 Iss. 1, pp [12][13][14][15][16][17]. This is an open access article published by the IET and CEPRI under the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/) C 4 F 7 N/CO 2 gas mixture shows a saturation increase trend with the mixing ratio.…”