Open AccessThe role of humidity and UV-C emission in the inactivation of B. subtilis spores during atmospheric-pressure dielectric barrier discharge treatment
Author(s) -
Friederike Kogelheide,
Farina Voigt,
Bastian Hillebrand,
Ralf Moeller,
Felix M. Fuchs,
Andrew Gibson,
Peter Awakowicz,
Katharina Stapelmann,
Marcel Fiebrandt
Publication year - 2020
Publication title -
journal of physics. d, applied physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.857
H-Index - 198
eISSN - 1361-6463
pISSN - 0022-3727
DOI - 10.1088/1361-6463/ab77cc
Subject(s) - dielectric barrier discharge , spore , chemistry , ozone , relative humidity , volume (thermodynamics) , context (archaeology) , bacterial spore , bacillus subtilis , atmospheric pressure , humidity , analytical chemistry (journal) , plasma , environmental chemistry , endospore , microbiology and biotechnology , bacteria , electrode , organic chemistry , meteorology , paleontology , physics , genetics , quantum mechanics , biology
Experiments are performed to assess the inactivation of Bacillus subtilis spores using a non-thermal atmospheric-pressure dielectric barrier discharge. The plasma source used in this study is mounted inside a vacuum vessel and operated in controlled gas mixtures. In this context, spore inactivation is measured under varying nitrogen/oxygen and humidity content and compared to spore inactivation using ambient air. Operating the dielectric barrier discharge in a sealed vessel offers the ability to distinguish between possible spore inactivation mechanisms since different process gas mixtures lead to the formation of distinct reactive species. The UV irradiance and the ozone density within the plasma volume are determined applying spectroscopic diagnostics with neither found to fully correlate with spore inactivation. It is found that spore inactivation is most strongly correlated with the humidity content in the feed gas, implying that reactive species formed, either directly or indirectly, from water molecules are strong mediators of spore inactivation.