Inactivation of Salmonella by nitrogen gas plasma generated by a static induction thyristor as a pulsed power supply
Inactivation of Salmonella by nitrogen gas plasma generated by a static induction thyristor as a pulsed power supply
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DOI：
10.1016/j.foodcont.2014.12.012
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发表时间：
2015-06-01
期刊：
影响因子：
6
通讯作者：
Sakudo, Akikazu
中科院分区：
文献类型：
--
作者：
Maeda, Kojiro;Toyokawa, Yoichi;Sakudo, Akikazu
就食品卫生而言，沙门氏菌是食源性感染的最重要病原体之一。在这项研究中，我们调查是否N-2气体等离子体，通过施加一个短的高压脉冲N-2使用静电感应晶闸管电源（1.5千脉冲每秒），表现出杀菌/消毒效果对沙门氏菌。沙门氏菌活细胞数有效地减少，小数减少时间（D值）为0.178 min（初始斜率）和3.105 min（单斜率近似）。等离子体处理改变了沙门氏菌的表面结构，通过扫描电子显微镜观察。此外，该处理诱导了O抗原的显著降解。聚合酶链反应（PCR）分析也表明沙门氏菌基因组DNA被等离子体处理损伤。在气体等离子体装置的操作过程中观察到反应性化学产物（过氧化氢样化学品）、紫外线（UV-A）和轻微的温度升高。活细胞数与每种潜在杀菌因子的强度被用来确定沙门氏菌消毒的主要机制。虽然同等水平的UV-A或热处理不能杀灭沙门氏菌，但用低浓度的过氧化氢处理能有效地灭活细菌。我们的研究结果表明，N-2气体等离子体产生反应性化学物质，改变沙门氏菌的成分，如细胞表面以及破坏基因组DNA。这些活性物质的联合作用是诱导细胞死亡。(C)2014爱思唯尔有限公司版权所有。
Salmonella is one of the most important causative agents of food borne infections in terms of food hygiene. In this study, we investigated whether N-2 gas plasma, generated by applying a short high-voltage pulse to N-2 using a static induction thyristor power supply (1.5 kilo pulse per second), exhibited a bactericidal/disinfecting effect against Salmonella. Viable cell number of Salmonella was efficiently decreased with a decimal reduction time (D value) of 0.178 min (initial slope) and 3.105 min (single-slope approximation). Plasma treatment altered the surface structure of Salmonella, as observed by scanning electron microscopy. In addition, this treatment induced a marked degradation in O antigen. Polymerase chain reaction (PCR) analysis also suggested that the Salmonella genomic DNA was damaged by the plasma treatment. Reactive chemical products (hydrogen peroxide-like chemicals), ultraviolet light (UV-A) and slight temperature elevations were observed during the operation of the gas plasma device. Viable cell number versus intensity of each potential bactericidal factor were used to identify the primary mechanism of disinfection of Salmonella. Although equivalent levels of UV-A or heat treatment did not inactivate Salmonella, treatment with a low concentration of hydrogen peroxide efficiently inactivated the bacteria. Our results suggest the N-2 gas plasma generates reactive chemical species that alter components of Salmonella such as the cell surface as well as damaging the genomic DNA. The combined effect of these reactive species is to induce cell death. (C) 2014 Elsevier Ltd. All rights reserved.