Effect of nanosecond pulsed electric field on Escherichia coli in water: inactivation and impact on protein changes

Abstract

Aims: This article shows the effect of nanosecond pulsed electric field (nsPEF) on Escherichia coli, which could imply a durable change in protein expressions and then impacted the phenotype of surviving bacteria that might lead to increase pathogenicity. Methods and Results: The effects of nsPEF on E. coli viability and membrane permeabilization were investigated. One log 10 reduction in bacterial counts was achieved at field strength of 10 7 V m À1 with a train of 500 successive pulses of 60 9 10 À9 s. Incubation of germs after treatment with propidium iodide showed that membrane permeabilization was reversible. Possible protein changes of surviving bacteria were checked to assess potential phenotypical changes using two-dimensional electrophoresis. In our study, after 40 generations, only UniProt #P39187 was up-regulated with P ≤ 0Á05 compared with the control and corresponded to the uncharacterized protein YtfJ. Antibiograms were used to check whether or not the pattern of cultivable bacteria after nsPEF deliveries changed. Conclusions:The results tend to show that nsPEFs are able to inactivate bacteria and have probably no serious impact in E. coli protein patterns. Significance and Impact of the Study: The use of nsPEF is a safe promising new nonthermal method for bacterial inactivation in the food processing and environmental industry.

600-ns pulsed electric fields affect inactivation and antibiotic susceptibilities of Escherichia coli and Lactobacillus acidophilus

“…In the present study we show in vitro results for the efficacy of 600-ns PEF to inactivate Escherichia coli and Lactobacillus acidophilus. While the effects of nsPEF have been studied on E. coli (Chalise et al 2006;Perni et al 2007;Guionet et al 2014Guionet et al , 2015Novickij et al 2018) and other species such as Staphylococcus aureus (Chaturongakul and Kirawanich 2012; Vadlamani et al 2018;Novickij et al 2019), Salmonella typhimurium (Perni et al 2007) and Bacillus subtilis (Katsuki et al 2002); we chose to compare the effects of E. coli with L. acidophilus for two reasons. First, several studies have suggested that cell size and shape play a critical role in transmembrane potential charging and subsequent membrane pore formation (Kandušer and Miklavčič 2008;Khan and El-Hag 2011).…”

Perspectives on using pulsed electric field to enhance biogas yield in anaerobic digestion

“…While some cell lines, e.g., U937 and Jurkat cells 52 , show signifi cant changes, others do not react in the same way. Studies involving E. coli did not show signifi cant changes in protein pattern 53 .…”

Pulsed electric field and mild heating for milk processing: a review on recent advances

“…For instance, the development of generators with more potent electrical fields operating with pulse widths in the nanosecond region are necessary. These new generators have to operate in accordance with reduced energy demand, have minimal heating effect, and spark generation between the electrodes …”

“…This condition can be achieved by applying high‐intensity electric pulses (varying between 15 and 60 kV cm −1 among different microorganisms) for short periods (a few microseconds) in the food matrix . Moreover, the effect of PEF treatment varies among microorganisms and between vegetative and spore forms …”

“…However, the scientific evidence about the inactivation of microorganisms and enzymes in milk and derived products by PEF technology has shown contrasting effects . It is important to mention that further developments in the project of PEF equipment, in order to deliver more intense (beyond 100 kV cm −1 ) and shorter electric pulses (in the nanosecond region) than the current PEF systems, are necessary to improve and strengthen the role of PEF as the main processing technology in the milk industry. An interesting alternative to enhance the impact of PEF on milk microorganisms and enzymes could be its association with other technological approaches, such as mild heating (below pasteurization conditions and exerting a supporting role for PEF treatment).…”