Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany
Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany.
Appl Environ Microbiol. 2018 Oct 17;84(21). doi: 10.1128/AEM.01163-18. Print 2018 Nov 1.
Microorganisms are predominantly organized in biofilms, where cells live in dense communities and are more resistant to external stresses than are their planktonic counterparts. With experiments, the susceptibility of biofilms to a nonthermal plasma treatment (plasma source, kINPen09) in terms of growth, survival, and cell viability was investigated. strain SC5314 (ATCC MYA-2876) was plasma treated for different time periods (30 s, 60 s, 120 s, 180 s, 300 s). The results of the experiments, encompassing CFU, fluorescence Live/Dead, and 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide salt (XTT) assays, revealed a negative influence of the plasma treatment on the proliferation ability, vitality, and metabolism of biofilms, respectively. Morphological analysis of plasma-treated biofilms using atomic force microscopy supported the indications for lethal plasma effects concomitant with membrane disruptions and the loss of intracellular fluid. Yielding controversial results compared to those of other publications, fluorescence and confocal laser scanning microscopic inspection of plasma-treated biofilms indicated that an inactivation of cells appeared mainly on the bottom of the biofilms. If this inactivation leads to a detachment of the biofilms from the overgrown surface, it might offer completely new approaches in the plasma treatment of biofilms. Because of plasma's biochemical-mechanical mode of action, resistance of microbial cells against plasma is unknown at this state of research. Microbial communities are an increasing problem in medicine but also in industry. Thus, an efficient and rapid removal of biofilms is becoming increasingly important. With the aid of the kINPen09, a radiofrequency plasma jet (RFPJ) instrument, decisive new findings on the effects of plasma on biofilms were obtained. This work showed that the inactivation of biofilms takes place mainly on the bottom, which in turn offers new possibilities for the removal of biofilms by other strategies, e.g., mechanical treatment. This result demonstrated that nonthermal atmospheric pressure plasma is well suited for biofilm decontamination.
微生物主要以生物膜的形式存在，在生物膜中，细胞生活在密集的群落中，比浮游细胞更能抵抗外部压力。通过实验，研究了非热等离子体处理（等离子体源，kINPen09）对生物膜生长、存活和细胞活力的影响。将 SC5314 菌株（ATCC MYA-2876）用等离子体处理不同的时间（30 s、60 s、120 s、180 s、300 s）。实验结果包括 CFU、荧光死活、2,3-双-(2-甲氧基-4-硝基-5-磺苯基)-2H-四唑-5-羧基苯胺盐（XTT）检测，分别表明等离子体处理对生物膜的增殖能力、活力和代谢有负面影响。原子力显微镜对等离子体处理生物膜的形态分析支持了等离子体致死效应的存在，同时伴随着膜破裂和细胞内液体的流失。与其他出版物的结果相比，产生了有争议的结果，对等离子体处理生物膜的荧光和共聚焦激光扫描显微镜检查表明，细胞失活主要发生在生物膜的底部。如果这种失活导致生物膜从过度生长的表面脱落，它可能为等离子体处理生物膜提供全新的方法。由于等离子体的生化机械作用模式，目前研究状态下微生物细胞对等离子体的抗性是未知的。微生物群落是医学和工业中日益严重的问题。因此，高效快速地去除生物膜变得越来越重要。借助 kINPen09 射频等离子体射流（RFPJ）仪器，获得了关于等离子体对生物膜影响的决定性新发现。这项工作表明，生物膜的失活主要发生在底部，这反过来又为通过其他策略（例如机械处理）去除生物膜提供了新的可能性。这一结果表明，非热大气压等离子体非常适合生物膜去污。
