Abstract
Aims
- This study was conducted to investigate the inactivation kinetics of Bacillus cereus vegetative cells upon exposure to low-temperature nitrogen gas plasma and to reveal the mode of inactivation by transcriptome profiling.
Methods and Results
- Exponentially growing B. cereus cells were filtered and put on agar plates. The plates, carrying the filters with the vegetative cells, were placed into low-temperature nitrogen gas plasma at atmospheric pressure. After different exposure times, the cells were harvested for RNA extraction and enumeration. The RNA was used to perform whole-transcriptome profiling using DNA microarrays. The transcriptome profile showed a large overlap with profiles obtained from conditions generating reactive oxygen species in B. cereus. However, excess radicals such as peroxynitrite, hydroxyl and superoxide could not be detected using radical-specific fluorescence staining. Lack of UV-specific responses including factors involved in DNA damage repair is in line with the absence of UV-specific emission in the afterglow of the nitrogen gas plasma as analysed using optical emission spectroscopy (OES).
Conclusions
- Antibacterial activity of nitrogen gas plasma is not based on UV radiation. Exposure to nitrogen gas plasma leads to oxidative stress and inactivation of targeted cells. A secondary oxidative stress with the indicative formation of reactive oxygen species within cells could not be observed.
Significance and Impact of the Study
- This study represents the first investigation of differential gene expression on a genome-wide scale in B. cereus following nitrogen gas plasma exposure. This study may help to design economically feasible, safe and effective plasma decontamination devices
Original language | English |
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Pages (from-to) | 689-702 |
Journal | Journal of Applied Microbiology |
Volume | 115 |
Issue number | 3 |
DOIs | |
Publication status | Published - 2013 |
Keywords
- atmospheric-pressure
- escherichia-coli
- argon plasma
- in-vitro
- sterilization
- inactivation
- identification
- bacteria
- efficacy
- stress