scholarly journals Plasma-Activated Water (PAW) as a Disinfection Technology for Bacterial Inactivation with a Focus on Fruit and Vegetables

Foods ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 166
Author(s):  
Aswathi Soni ◽  
Jonghyun Choi ◽  
Gale Brightwell
Keyword(s):  
Fruit And Vegetables ◽  
Atmospheric Plasma ◽  
Model Systems ◽  
Thermal Treatments ◽  
Bacterial Cells ◽  
Bacterial Inactivation ◽  
Gas Temperature ◽  
Bacterial Strains ◽  
Sensory Qualities ◽  
Plasma Activated Water

Plasma-activated water (PAW) is generated by treating water with cold atmospheric plasma (CAP) using controllable parameters, such as plasma-forming voltage, carrier gas, temperature, pulses, or frequency as required. PAW is reported to have lower pH, higher conductivity, and higher oxygen reduction potential when compared with untreated water due to the presence of reactive species. PAW has received significant attention from researchers over the last decade due to its non-thermal and non-toxic mode of action especially for bacterial inactivation. The objective of the current review is to develop a summary of the effect of PAW on bacterial strains in foods as well as model systems such as buffers, with a specific focus on fruit and vegetables. The review elaborated the properties of PAW, the effect of various treatment parameters on its efficiency in bacterial inactivation along with its usage as a standalone technology as well as a hurdle approach with mild thermal treatments. A section highlighting different models that can be employed to generate PAW alongside a direct comparison of the PAW characteristics on the inactivation potential and the existing research gaps are also included. The mechanism of action of PAW on the bacterial cells and any reported effects on the sensory qualities and shelf life of food has been evaluated. Based on the literature, it can be concluded that PAW offers a significant potential as a non-chemical and non-thermal intervention for bacterial inactivation, especially on food. However, the applicability and usage of PAW depend on the effect of environmental and bacterial strain-based conditions and cost-effectiveness.

scholarly journals Effect of Non-Thermal Atmospheric Plasma on Food-Borne Bacterial Pathogens on Ready-to Eat Foods: Morphological and Physico-Chemical Changes Occurring on the Cellular Envelopes

Foods ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 1865
Author(s):  
Tamara Calvo ◽  
Miguel Prieto ◽  
Avelino Alvarez-Ordóñez ◽  
Mercedes López
Keyword(s):  
Salmonella Enteritidis ◽  
Structural Changes ◽  
Membrane Integrity ◽  
Atmospheric Plasma ◽  
Bacterial Cells ◽  
Bacterial Inactivation ◽  
Cellular Targets ◽  
E Coli ◽  
Physico Chemical ◽  
Potential Applications

Currently, there is a need for new technological interventions to guarantee the microbiological safety of ready-to-eat (RTE) foods. Non-thermal atmospheric plasma (NTAP) has emerged as a promising strategy for inactivating microorganisms on thermo-sensitive foods, and the elucidation of its mechanisms of action will aid the rational optimization and industrial implementation of this technology for potential applications in the food industry. In this study, the effectiveness of NTAP for inactivating strains of Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli O157:H7 and Listeria monocytogenes contaminating the surface of different sliced RTE foods (“chorizo”, salami, bacon, smoked salmon, tofu and apple) was investigated. In addition, to further assess the bacterial inactivation mechanisms of NTAP, the morphological and physico-chemical damages in bacterial cells were analyzed. NTAP was effective for the surface decontamination of all products tested and, especially, of cut apple, where the microbial populations were reduced between 1.3 and 1.8 log units for the two Salmonella strains and E. coli O157: H7, respectively, after 15 min of exposure. In the rest of foods, no significant differences in the lethality obtained for the E. coli O157:H7 strain were observed, with inactivation rates of between 0.6 and 0.9 log cycles after a 15-min treatment. On the other hand, the strains from the rest of pathogenic microorganisms studied were extremely resistant on tofu, where barely 0.2–0.5 log units of inactivation were achieved after 15 min of plasma exposure. S. Enteritidis cells treated for 10 min exhibited noticeable morphological and structural changes, as observed by transmission electron microscopy, which were accompanied by a loss in membrane integrity, with an increased leakage of intracellular components and uptake of propidium iodide and marked changes in regions of their FTIR spectra indicating major alterations of the cell wall components. Overall, this indicates that loss of viability was likely caused for this microorganism by a significant damage in the cellular envelopes. However, the plasma-treated cells of L. monocytogenes did not show such obvious changes in morphology, and exhibited less marked effects on the integrity of their cytoplasmic membrane, what suggests that the death of this pathogenic microorganism upon NTAP exposure is more likely to occur as a consequence of damages in other cellular targets.

scholarly journals Evaluation of non-thermal effect of microwave radiation and its mode of action in bacterial cell inactivation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Priyanka Shaw ◽  
Naresh Kumar ◽  
Sohail Mumtaz ◽  
Jun Sup Lim ◽  
Jung Hyun Jang ◽  
...  
Keyword(s):  
Thermal Effect ◽  
Microwave Radiation ◽  
Bacterial Cell ◽  
Mode Of Action ◽  
Surface Damage ◽  
Peak Frequency ◽  
Viable Count ◽  
Bacterial Inactivation ◽  
Bacterial Strains ◽  
Log Reduction

AbstractA growing body of literature has recognized the non-thermal effect of pulsed microwave radiation (PMR) on bacterial systems. However, its mode of action in deactivating bacteria has not yet been extensively investigated. Nevertheless, it is highly important to advance the applications of PMR from simple to complex biological systems. In this study, we first optimized the conditions of the PMR device and we assessed the results by simulations, using ANSYS HFSS (High Frequency Structure Simulator) and a 3D particle-in-cell code for the electron behavior, to provide a better overview of the bacterial cell exposure to microwave radiation. To determine the sensitivity of PMR, Escherichia coli and Staphylococcus aureus cultures were exposed to PMR (pulse duration: 60 ns, peak frequency: 3.5 GHz) with power density of 17 kW/cm2 at the free space of sample position, which would induce electric field of 8.0 kV/cm inside the PBS solution of falcon tube in this experiment at 25 °C. At various discharges (D) of microwaves, the colony forming unit curves were analyzed. The highest ratios of viable count reductions were observed when the doses were increased from 20D to 80D, which resulted in an approximate 6 log reduction in E. coli and 4 log reduction in S. aureus. Moreover, scanning electron microscopy also revealed surface damage in both bacterial strains after PMR exposure. The bacterial inactivation was attributed to the deactivation of oxidation-regulating genes and DNA damage.

scholarly journals IN VITRO ANTIOXIDANT AND IN VIVO ANTIDIABETIC ACTIVITY OF TWO POTENTIAL PROBIOTIC ENTEROCOCCUS SPP. ON ALLOXAN-INDUCED DIABETIC RATS

2021 ◽  
pp. 94-98
Author(s):  
KAMNI RAJPUT ◽  
RAMESH CHANDRA DUBEY
Keyword(s):  
Diabetic Rats ◽  
Antidiabetic Activity ◽  
Control Group ◽  
Albino Rats ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Animal Group ◽  
Enterococcus Spp

Objective: In vitro antioxidant activity, in vivo antidiabetic property and intestinal attachment by two potential probiotic bacterial strains, namely, Enterococcus faecium and Enterococcus hirae were studied using albino rats. Methods: Antioxidant the activity was assessed using 2,2-Diphenyl-1-picrylhydrazyl radicals scavenging assay. Alloxan was administered intraperitoneally to induce diabetic conditions in experimental rats. Animals were treated with oral administration of Enterococcus spp., such as E. faecium, and E. hirae isolated from goat and sheep milk. The control animal group received normal saline for the same days. Glibenclamide drug was used as a positive control against probiotic bacterial cells. Results: However, administration of probiotic bacterial strains E. faecium and E. hirae, in albino rats significantly (p<0.05) at varying doses lowered blood glucose levels in diabetic rats as compared to the diabetic control group. Both the species of Enterococcus increased the bodyweight of experimental rats. However, E. faecium was the best antidiabetic strain having the antioxidant activities also in comparison to E. hirae. The attachment of probiotic bacterial cells E. faecium on the rat’s intestine wall against pathogens was examined. Furthermore, E. faecium showed its aggregation with pathogens by attachment of the intestines of albino rats. This showed that both the bacterial strains exhibited in vivo antidiabetic effect. Conclusion: The results of this study showed that probiotic bacteria possess antioxidant, antidiabetic activities, and attachment of intestine.

Reactive radical-driven bacterial inactivation by hydrogen-peroxide-enhanced plasma-activated-water

2017 ◽  
Vol 226 (13) ◽  
pp. 2887-2899 ◽  
Author(s):  
Songjie Wu ◽  
Qian Zhang ◽  
Ruonan Ma ◽  
Shuang Yu ◽  
Kaile Wang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Bacterial Inactivation ◽  
Plasma Activated Water

scholarly journals Effects of natural antimicrobials on bacterial cell hydrophobicity, adhesion, and zeta potential / Vpliv naravnih protimikrobnih snovi na bakterijsko hidrofobnost, adhezijo in zeta potencial

2016 ◽  
Vol 67 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Marija Kurinčič ◽  
Barbara Jeršek ◽  
Anja Klančnik ◽  
Sonja Smole Možina ◽  
Rok Fink ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Bacterial Adhesion ◽  
Bacterial Cell ◽  
Early Stage ◽  
Experimental Studies ◽  
Adhesion Prevention ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Natural Antimicrobials ◽  
Cell Hydrophobicity

Abstract Interactions between bacterial cells and contact materials play an important role in food safety and technology. As bacterial strains become ever more resistant to antibiotics, the aim of this study was to analyse adhesion of selected foodborne bacterial strains on polystyrene surface and to evaluate the effects of natural antimicrobials on bacterial cell hydrophobicity, adhesion, and zeta potential as strategies of adhesion prevention. The results showed strain-specific adhesion rate on polystyrene. The lowest and the highest adhesion were found for two B. cereus lines. Natural antimicrobials ferulic and rosmarinic acid substantially decreased adhesion, whereas the effect of epigallocatechin gallate was neglectful. Similar results were found for the zeta potential, indicating that natural antimicrobials reduce bacterial adhesion. Targeting bacterial adhesion using natural extracts we can eliminate potential infection at an early stage. Future experimental studies should focus on situations that are as close to industrial conditions as possible.

The strategy of editing and modification of the genomes of bacterial viruses

Bacteriology ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. 48-59
Author(s):  
A.S. Schurova ◽  
◽  
V.A. Bannov ◽  
A.V. Popova ◽  
◽  
...  
Keyword(s):  
Antimicrobial Agents ◽  
Phage Genome ◽  
Genetically Engineered ◽  
Bacterial Cells ◽  
Practical Application ◽  
Bacterial Strains ◽  
Recombinant Phage ◽  
Research Problems ◽  
Genomic Editing

In recent decades, a major problem for health systems around the world is the wide spread of bacterial pathogens that are resistant to various antimicrobial agents. A possible approach to solving this problem is the use of bacteriophages, viruses that specifically infect bacterial cells, as well as enzymes and proteins encoded in their genomes. The development of genomic editing technologies, including those based on CRISPR-Cas editing, makes it possible to create genetically engineered or recombinant phage particles with desired properties that are important for further practical application. In this review, we consider issues related to the characterization of bacteriophages as biological objects and as promising candidates for controlling the spread of antibioticresistant bacterial strains. We discuss modern approaches and strategies for modifying the phage genomes using various methods of genetic engineering and molecular biology to solve a variety of practical and research problems. Keywords: bacteriophages, phage genome editing, CRISPR-Cas system

scholarly journals Effect of milk chocolate supplementation with lyophilised Lactobacillus cells on its attributes

2010 ◽  
Vol 28 (No. 5) ◽  
pp. 392-406 ◽  
Author(s):  
D. Żyżelewicz ◽  
E. Nebesny ◽  
I. Motyl ◽  
Z. Libudzisz
Keyword(s):  
Ambient Temperature ◽  
High Temperatures ◽  
Functional Food ◽  
Lactobacillus Casei ◽  
Probiotic Bacteria ◽  
Live Cells ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Milk Chocolate ◽  
Live Bacterial Cells

Manufacturing of novel foodstuffs supplemented with live probiotic bacteria has recently been intensively investigated. The supplementation of confectionery with probiotics is troublesome since some unit technological processes are conducted at high temperatures and the products are usually stored at ambient temperature. Our group has developed a method of the production of milk chocolate, sweetened with either sucrose or isomalt and aspartame, containing 32, 36, or 40 g/100 g fat, and supplemented with live cells of probiotic bacterial strains: Lactobacillus casei and paracasei. This new milk chocolate displayed the same sensory properties as the reference, probiotic-free chocolate. The number of live bacterial cells was maintained at the functional level of 10<sup>6</sup> &divide; 10<sup>8</sup> cfu/g after keeping for 12 months irrespective of the temperature. The highest number of live probiotic bacteria survived in the chocolate kept at 4&deg;C. Thus the product can be regarded as functional food.

Cold atmospheric plasma activated water as a prospective disinfectant: the crucial role of peroxynitrite

2018 ◽  
Vol 20 (23) ◽  
pp. 5276-5284 ◽  
Author(s):  
Renwu Zhou ◽  
Rusen Zhou ◽  
Karthika Prasad ◽  
Zhi Fang ◽  
Robert Speight ◽  
...  
Keyword(s):  
Crucial Role ◽  
Atmospheric Plasma ◽  
Cold Atmospheric Plasma ◽  
Plasma Activated Water

Here the possibility of plasma-activated water being a green disinfectant, whose bioactivity is closely linked to peroxynitrite generation, was demonstrated.

scholarly journals Utilization of Mn-Doped ZnSe/ZnS Core/Shell Quantum Dots for Rapid Detection of Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Thi-Diem Bui ◽  
Quang-Liem Nguyen ◽  
Thi-Bich Luong ◽  
Van Thuan Le ◽  
Van-Dat Doan
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Quantum Dots ◽  
Fluorescent Labeling ◽  
Core Shell ◽  
Bacterial Cells ◽  
Bacterial Strains ◽  
Methicillin Resistant ◽  
E Coli ◽  
Mn Doped

In this study, Mn-doped ZnSe/ZnS core/shell quantum dots (CSQDs) were synthesized in aqueous solution using polyethylene glycol as a surface stabilizer and successfully applied in the detection of Escherichia coli O157:H7 and methicillin-resistant Staphylococcus aureus (MRSA) for the first time. The CSQDs were conjugated with anti-E. coli antibody and anti-MRSA antibody via protein A supported by 1-ethyl-3-(-3-dimethylaminopropyl)carbodiimide hydrochloride for fluorescent labeling of the intact bacterial cells. The detection was performed for the bacterial strains cultivated in Luria-Bertani liquid medium. The obtained results indicate that E. coli O157:H7 and MRSA can be detected within 30 min at a high sensitivity of 101 CFU/mL. This labeling method based on the highly fluorescent CSQDs may have great potential for use in the food industry to check and prevent outbreaks of foodborne illness.

scholarly journals Evaluation of treatment and disinfection of water using cold atmospheric plasma

2016 ◽  
Vol 14 (4) ◽  
pp. 609-616 ◽  
Author(s):  
Zohreh Rashmei ◽  
Hamid Bornasi ◽  
Mahmood Ghoranneviss
Keyword(s):  
Atmospheric Plasma ◽  
Bacterial Inactivation ◽  
Electrical Fields ◽  
E Coli ◽  
Colony Forming Units ◽  
Escherichia Coli Bacteria ◽  
Physical And Chemical ◽  
Inactivation Of Bacteria ◽  
Number Of Bacteria ◽  
Research Show

In this paper, the disinfection of water is investigated using plasma spark treatment and the results are compared with conventional techniques. Inactivation of the Enterococcus faecalis and Escherichia coli bacteria is considered in the treatment process of water by the plasma spark. For this purpose, many physical and chemical parameters of water are measured and the obtained results demonstrate a reduction of 8-log in colony forming units of E. coli and E. faecalis at 15 minutes and 12 minutes, respectively. The results of this research show that no ozone is produced during the plasma spark treatment. Moreover, inactivation of a large number of bacteria without any change of pH shows that pH is not the cause of the bacterial inactivation. It is concluded that the main causes of the inactivation of bacteria in the treated water are H2O2 molecules and the electrical fields generated by plasma.

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