Plasmainaktivierung von mikrobiellen Biofilmen
Zusammenfassung der Projektergebnisse
The projects multidisciplinary approach to the inactivation of bacterial spores and biofilms by lowtemperature plasma treatment has revealed promising insights into the discharge dynamics, specifically the decoupling of relevant plasma parameters, and the importance of different mechanisms of action for inactivation of B. subtilis spores and biofilms. Two types of low-temperature discharges were studied, an atmospheric pressure dielectric barrier discharge (DBD) and a low-pressure inductively coupled plasma system (DICP). Each of the two systems is suitable for different use-cases and offers unique operating regimes. The plasma systems were studied by a combined experimental and theoretical approach, where extensive diagnostic methods were used to measure fundamental plasma parameters and densities of reactive species, which were then used as input parameters for newly developed theoretical models, and their validation. For both discharges a decoupling between UV photon emission and production of relevant reactive species is achieved. The biological part of the project was able to provide detailed insight into the inactivation efficacy of B. subtilis by low-temperature plasma treatment, the morphological changes induced by plasma treatment, as well as the stress response and survival mechanism of corresponding biofilms under plasma exposure. Different strains of B. subtilis, e.g. sporulation deficient strains or strains lacking exopolysaccharides (EPS), were used to selectively reveal survival mechanisms. Exposure to UV-C radiation is shown to be effective for spore inactivation, but insufficient for biofilms. Matrix EPS of biofilms provide increased resistance to UV-C radiation, which results in reactive species being the dominant inactivating mechanism for multi-cellular structures. Overall, the project has provided significant insight into the potential for tuning of the plasma systems for inactivation of bacterial spores and biofilms, by advancing our understanding of different operating regimes and mechanisms of action for the inactivation process.
Projektbezogene Publikationen (Auswahl)
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The role of humidity and UV-C emission in the inactivation of B. subtilis spores during atmospheric-pressure dielectric barrier discharge treatment. Journal of Physics D: Applied Physics, 53(29), 295201.
Kogelheide, Friederike; Voigt, Farina; Hillebrand, Bastian; Moeller, Ralf; Fuchs, Felix; Gibson, Andrew R.; Awakowicz, Peter; Stapelmann, Katharina & Fiebrandt, Marcel
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Decoupling NO production and UV emission intensity over the E-H mode transition in a low-pressure inductively coupled plasma device.
L. Schücke, A. N. Torres Segura, I. Korolov, P. Awakowicz & A. R. Gibson
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Multifactorial resistance of Bacillus subtilis spores to low-pressure plasma sterilization. Applied and Environmental Microbiology, 90(1).
Muratov, Erika; Rosenbaum, Florian P.; Fuchs, Felix M.; Ulrich, Nikea J.; Awakowicz, Peter; Setlow, Peter & Moeller, Ralf
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Numerical investigation of vacuum ultra-violet emission in Ar/O2 inductively coupled plasmas. Plasma Sources Science and Technology, 33(9), 095008.
Osca, Engelbrecht Michel; Jenderny, Jonathan; Hylla, Henrik; Filla, Dominik; Awakowicz, Peter; Korolov, Ihor; Ridgers, Christopher P. & Gibson, Andrew R.
