High voltage electrical discharge (gas and liquid) plasmas are new developing techniques used for food and water decontamination. This study investigates the influence of high voltage gas phase plasma treatment on several parameters: inactivation of Escherichia coli K12, recovery, proteomic analyses, cellular leakage and influence of pH and generated H₂O₂ species on inactivation of the E. coli cells. Samples were treated in a glass reactor with a point-to-plate electrode configuration. Electrical conductivity (100 and 800 μS/cm), polarity (+/−), time (5 and 10 min) and frequency (60, 90 and 120 Hz) were chosen in order to determine their influence on listed parameters. Statistical analyses were obtained to optimize conducted treatments. Treatment regime of 90 Hz, positive polarity, 100 μS/cm and 10 min resulted in the highest reduction (7.8 log₁₀ CFU/mL) of E. coli. Recovery of cells after the treatment suggested oxidative stress overcome.

Industrial relevance

Plasma processing is an energy effective process, comparing to traditional thermal processes like pasteurization and sterilization. Plasma treated liquid remains at low temperature, which lowers electrical energy consumption during industrial processes. The proposed study investigates the possible application of high voltage gas phase electrical discharge plasmas for inactivation of Escherichia coli K12 MG1655 in water. The main aim was to confirm effectiveness of plasma treatment conducted in argon (which is uninfected by plasma and can be recycled) on inactivation and cell recovery of E. coli K12. This research is a first step towards the development of the gas phase plasma technology for disinfection of liquids. However, future development, optimization and application of this technology for food sterilization will lead to acceptable ecological regulations like lowering greenhouse gas emissions.

中文翻译：

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高压气相等离子体处理后大肠杆菌的定量微生物评估

高压放电（气体和液体）等离子体是用于食品和水净化的新兴技术。这项研究调查了高压气相等离子体处理对几个参数的影响：大肠杆菌K12的失活，回收率，蛋白质组学分析，细胞渗漏以及pH值和所产生的H ₂ O ₂种类对大肠杆菌失活的影响。细胞。在具有点对板电极构造的玻璃反应器中处理样品。选择了电导率（100和800μS/ cm），极性（+/-），时间（5和10分钟）和频率（60、90和120 Hz），以确定它们对所列参数的影响。获得统计分析以优化所进行的治疗。90 Hz，正极性，100μS/ cm和10分钟的处理方案导致大肠杆菌的最大减少量（7.8 log ₁₀  CFU / mL）。处理后细胞的恢复提示氧化应激得到克服。

行业相关性

与传统的热过程（如巴氏灭菌和灭菌）相比，等离子处理是一种节能的过程。经过等离子处理的液体保持低温，从而降低了工业过程中的电能消耗。拟议的研究调查了高压气相放电等离子体在水中灭活大肠杆菌K12 MG1655的可能应用。主要目的是确认在氩气中进行血浆处理（不受血浆感染并可以循环使用）对大肠杆菌的灭活和细胞回收的有效性。K12。这项研究是开发用于液体消毒的气相等离子体技术的第一步。但是，该技术在食品灭菌中的未来发展，优化和应用将导致可接受的生态法规，例如降低温室气体排放。