Han L, Patil S, Boehm D, Milosavljević V, Cullen P J, Bourke P
School of Food Science and Environmental Health, Dublin Institute of Technology, Dublin, Ireland.
School of Food Science and Environmental Health, Dublin Institute of Technology, Dublin, Ireland School of Chemical Engineering, UNSW, Sydney, Australia.
Appl Environ Microbiol. 2015 Oct 30;82(2):450-8. doi: 10.1128/AEM.02660-15. Print 2016 Jan 15.
Atmospheric cold plasma (ACP) is a promising nonthermal technology effective against a wide range of pathogenic microorganisms. Reactive oxygen species (ROS) play a crucial inactivation role when air or other oxygen-containing gases are used. With strong oxidative stress, cells can be damaged by lipid peroxidation, enzyme inactivation, and DNA cleavage. Identification of ROS and an understanding of their role are important for advancing ACP applications for a range of complex microbiological issues. In this study, the inactivation efficacy of in-package high-voltage (80 kV [root mean square]) ACP (HVACP) and the role of intracellular ROS were investigated. Two mechanisms of inactivation were observed in which reactive species were found to either react primarily with the cell envelope or damage intracellular components. Escherichia coli was inactivated mainly by cell leakage and low-level DNA damage. Conversely, Staphylococcus aureus was mainly inactivated by intracellular damage, with significantly higher levels of intracellular ROS observed and little envelope damage. However, for both bacteria studied, increasing treatment time had a positive effect on the intracellular ROS levels generated.
大气冷等离子体（ACP）是一种很有前景的非热技术，对多种致病微生物有效。当使用空气或其他含氧气体时，活性氧（ROS）发挥着关键的灭活作用。在强氧化应激下，细胞会因脂质过氧化、酶失活和DNA裂解而受损。识别ROS并了解其作用对于推进ACP在一系列复杂微生物问题上的应用很重要。在本研究中，研究了包装内高压（80 kV[均方根]）ACP（HVACP）的灭活效果以及细胞内ROS的作用。观察到两种灭活机制，其中发现活性物质主要与细胞膜反应或损伤细胞内成分。大肠杆菌主要通过细胞渗漏和低水平的DNA损伤而被灭活。相反，金黄色葡萄球菌主要通过细胞内损伤而被灭活，观察到细胞内ROS水平显著更高，且细胞膜损伤较小。然而，对于所研究的两种细菌，延长处理时间对产生的细胞内ROS水平有积极影响。
