Effectiveness of slightly acidic electrolyzed water on bacteria reduction: in vitro and spray evaluation (original) (raw)
Related papers
Scientific Reports
The Influence of water source on the production of slightly acidic electrolyzed water (SAEW) and its sanitization efficacy were investigated. Two different water sources (tap water (TW) and underground water (UGW)) were applied to produce slightly acidic electrolyzed water (SAEW) at same setting current, with similar electrolyte flow rate (EFR) and concentration. Properties of SAEW were evaluated based on pH, Available chlorine concentration (ACC) and oxidation-reduction potential (ORP). Methods for the optimization of SAEW production process was examined to obtain high ACC value by implanting different types of electrolytes. Effect of ACC and pH of SAEW were evaluated in vitro towards inactivate foodborne pathogens. The results indicated that TW with hardness of 29 ppm produced effectively SAEW than through UGW (12 ppm) using electrolytes. Likewise, low water hardness could be reinforced by combining HCL with a salt (NaCl or KCL). The optimized SAEW production system was determined at 4% HCl + 2.0 M KCL with EFR of 2 mL/min and 4% HCl + 3.0 M KCL with EFR of 2 mL/min resulting in higher ACC value of 56.5 and 65.5 ppm, respectively using TW. Pathogenic vegetative cells were completely inactivated within 1 min of treatment in SAEW with 20 ppm. Viability observations using Confocal and TEM Microscopy, Flow cytometry, and antimicrobial activity were carried out to confirm the sanitizing effect and cell membrane disruption. Based on the experimental results obtained, it provides a foundation for future advancement towards commercial application of SAEW in the food and agricultural industries.
Effectiveness of electrolyzed water as a sanitizer for treating different surfaces
Journal of food protection, 2002
The effectiveness of electrolyzed (EO) water at killing Enterobacter aerogenes and Staphylococcus aureus in pure culture was evaluated. One milliliter (approximately 10(9) CFU/ml) of each bacterium was subjected to 9 ml of EO water or control water (EO water containing 10% neutralizing buffer) at room temperature for 30 s. Inactivation (reduction of > 9 log10 CFU/ ml) of both pathogens occurred within 30 s after exposure to EO water containing approximately 25 or 50 mg of residual chlorine per liter. The effectiveness of EO water in reducing E. aerogenes and S. aureus on different surfaces (glass, stainless steel, glazed ceramic tile, unglazed ceramic tile, and vitreous china) was also evaluated. After immersion of the tested surfaces in EO water for 5 min without agitation, populations of E. aerogenes and S. aureus were reduced by 2.2 to 2.4 log10 CFU/ cm2 and by 1.7 to 1.9 log10 CFU/cm2, respectively, whereas washing with control water resulted in a reduction of only 0.1 to 0.3...
Spatial disinfection potential of slightly acidic electrolyzed water
PLOS ONE, 2021
Slightly acidic electrolyzed water (SAEW) was developed by Japanese companies over 20 years ago. SAEW has the advantage of potent sterilizing action while being relatively safe. This study evaluated the potential application of SAEW in spatial disinfection. Prior to experiments involving spatial spraying, the ability of SAEW to remove seven type of microorganisms that cause food poisoning was studied in vitro. Results indicated that free chlorine in SAEW, even at a low concentration (30 mg/L), was able to remove Cladosporium cladosporioides, a typical airborne fungus that degrades food, and spores such as Bacillus subtilis, a hardy bacterium. In an experiment involving spatial spraying, 3.43 log10 CFU/100 L of Staphylococcus epidermidis was sprayed in a room-sized space; the same space was then sprayed with SAEW. The number of settling microbes was measured and the sterilizing ability of SAEW was assessed. Results indicated that the concentration of S. epidermidis in the space was c...
Microorganisms’ Killing: Chemical Disinfection vs. Electrodisinfection
Applied Engineering, 2019
Chlorination is the most used technique of killing microorganisms' in water through the potable water industry. Some outbreaks of water born disease, the definition of chlorine as a source of greatly toxic disinfection by-products (DBPs), and the appearance of recalcitrant microbes have conducted to revised regulation for the elimination of microorganisms and DBPs from potable water. Therefore, researching new disinfection techniques has been developed. Electrochemical disinfection or electrodisinfection (ED) has appeared as one of the more valuable alternatives to chlorination. Research employing a range of cell designs has illustrated ED to be efficient towards an interval of microbes. Nevertheless, in several cases, killing pathogens' performance seems to be linked to the production of chlorine species. The obvious dominance of chlorine in the form of the pathway of killing microbes' emerges the interrogation if ED is really more beneficial than chlorination in a matter of its demobilization performance and risk to generate DBPs. Convenient ED devices must be designed and monitored sophistically since the present state of non-monitored use of ED devices is not favorable in terms of hygienic and health risks considerations. Great works remain to be performed.
Electrolytic Method for Deactivation of Microbial Pathogens in Surface Water for Domestic Use
Electrochemical or electrolytic disinfection is one of the emerging technologies for treating drinking water and wastewater. This method gained much attention, especially because of its practical feasibility as there is no need for addition of chemicals or generation of toxic byproducts. In addition to this, the operational cost is also low. This work is thus aimed at studying the deactivation of waterborne pathogens from lake water by electrolytic disinfection. The electrolytic disinfection unit (EDU) was designed and examined for efficiency of deactivation of microbial pathogens in raw lake water. The batch scale experiments were performed to investigate the effect of aluminum electrodes with direct current (D.C.) supply on the inactivation efficiency of index microorganisms and pathogens namely Total coliforms, Faecal coliforms, E. coli and Faecal streptococci and pathogens, namely Salmonella spp. and Shigella spp. The optimum current intensity (Ampere (A)) and contact time for 80 to 95 % inactivation of pathogen indicators and pathogens were observed to be (1A 90 minutes) and (2A 90 minutes).
2013 Kansas City, Missouri, July 21 - July 24, 2013, 2013
This study investigated the loss of free chlorine (FC, the major germicidal component in MLAEW) over distance during spray, as affected by air temperature and initial FC concentration. The antimicrobial effect of MLAEW on airborne bacteria from an aviary laying-hen house was examined. MLAEW was prepared with two FC concentrations (app. 15 and 60 mg L -1 ), and was sprayed at three air temperatures (18, 25, 32°C). The original MLAEW solution and MLAEW aerosols collected at 0, 25, and 50 cm from the spray nozzle were analyzed for FC concentrations. Bacteria were immersed into these MLAEW samples and numerated for viable count after 0.5-, 2-, and 5-min treatments. MLAEW aerosols collected at 0 cm lost 11.7 -13.2% FC as compared to the original MLAEW solution. This initial loss was affected neither by the initial FC concentration (P = 0.13) nor by air temperature (P = 0.57). The rate of FC loss during travelling was 0.79 -0.87 % per centimeter of aerosol travel distance (% cm -1 ) at 18°C, 1.08 -1.15 % cm -1 at 25°C, and 1.35 -1.49 % cm -1 at 32°C. This travelling loss was affected by air temperature (P = 0.02), but not by initial FC concentration (P = 0.38). Bacteria were completely inactivated in 0.5 min when treated with MLAEW samples with FC > 16.8 mg L -1 , in 2 min when FC > 13.8 mg L -1 , and in 5 min when FC > 7.2 mg L -1 . Airborne bacteria from aviary hen house can be effectively inactivated by MLAEW with adequate FC concentration and contact time. During spray, antimicrobial efficacy of MLAEW aerosols decreased over distance due to FC loss which exacerbates at higher air temperature.
Background and Purpose: The burn unit is a suitable environment for growing of bacteria such as Pseudomonas, Acinetobacter, and Staphylococcus that appropriate disinfection can reduce these pathogens. The aim of this study was to evaluate the effect of different disinfectants on Gram-negative bacteria isolated from the surface of accidents and burn hospital in Yazd. Materials and Methods: In this study, 240 samples were randomly collected from different parts of accidents and burn hospital before and after disinfection. The samples were cultured on blood agar and Eusion-Metilen-Blue agar media in the Microbiology Laboratory of Medicine School of Shahid Sadoughi University in Yazd and Colony counting were determined. Identification was done by biochemical tests after incubation at 37° C for 48 hours. The studied disinfectants were Deconex 50AF, Descoscid, Epimax SC, and Silvosept. At last, data were analyzed with using paired t-test. Results: The Gram-negative bacteria were isolated from burn unit before disinfection included Pseudomonas aeruginosa, Escherichia coli, Proteus spp., Klebsiella spp., Acinetobacter spp., and Enterobacter spp. According to the results, all disinfectants reduced the pollution before and after disinfection; nevertheless, this reduction at the time of using Epimax SC and Silvosept only showed a significant difference for P. aeruginosa (P = 0.001 and 0.003) and for E. coli (P = 0.020 and 0.005), respectively. Conclusion: All disinfectants were effective on Gram-negative bacteria isolated from surfaces and had shown a significant difference only between P. aeruginosa and E. coli number before and after disinfection by Epimax SC and Silvosept. The most effective disinfectant on P. aeruginosa and E. coli was Epimax SC and Silvosept, respectively.
International journal of clinical and experimental medicine, 2015
The aim of this study was to investigate the in-vitro antimicrobial activity of usage and normal concentrations of electrolyzed water in hospital. In our study, the effects of different concentrations of electrolyzed water named Envirolyte® (Industries International Ltd., Estonia) on two gram positive, four gram negative standard strains and clinical isolates of four gram negative, two gram positive, one spore-forming bacillus and Myroides spp strains that lead to hospital infections were researched. The effects of different concentrations and different contact times of Envirolyte® electrolyzed water on cited strains were researched through method of qualitative suspension tests. Petri dishes fo bacteria have been incubated at 37°C 48 hours. Bactericidal disinfectant was interpreted to be effective at the end of the period due to the lack of growth. Solutions to which disinfectant were not added were prepared with an eye to control reproduction and controlcultures were made by using...
Proceedings of the Water Environment Federation, 2009
The burden of unsafe drinking water falls most heavily on those without access to water infrastructure, including people in the developing world. Unsafe water containing harmful bacteria, viruses, and parasites kills more than 1.6 million people a year in the developing world, many of them children. The long-term solution to the problem of waterborne illnesses in developing countries is to provide universal access to safe, pathogen-free, and reliable piped water supplies; unfortunately, this solution is decades away in much of the developing world due to the high capital costs of water infrastructure construction and maintenance. Treatment of drinking water at the point of use (POU) has demonstrated health benefits for people who have access only to microbially contaminated drinking water sources. Chlorine is widely used for drinking water disinfection, and has been applied for POU treatment, but it is often rejected by users due to taste and odor problems and toxic disinfection by-products. Drawbacks of chlorine disinfection have led to a search for alternative chemical disinfectants for POU treatment of drinking water. One such alternative is One Drop, an aqueous solution of natural ionic minerals, including silver, gold, aluminum and copper. These metal ions have been previously shown to have microbicidal properties when added to contaminated water. Metal-ion based disinfectants have the potential to be effective disinfectants when added in small quantities, without causing adverse human health effects or problems with undesirable taste and odor. In addition to inactivating microbes, One Drop may also interact with negatively charged microbes to facilitate settling or removal by filtration. In this work, One Drop was evaluated in the laboratory for its ability to reduce turbidity and indicator and pathogenic microorganisms in seeded test waters consisting of raw surface water. Reductions of E. coli B and coliphage MS-2 were measured in one-liter volumes of test water treated with 0, 1, 2, or 4 drops of disinfectant. There were appreciable reductions of microbial indicators in One Drop treated water. Reductions of >6 log 10 (>99.9999%) were observed for E. coli B and >5.5 log 10 for MS-2. Reductions generally increased over time and with increasing disinfectant concentration. Microbial reductions in test waters treated with One Drop were more rapid and extensive than in test waters without the addition of One Drop. We conclude that One Drop reduces concentrations of some representative indicator and pathogenic microorganisms in raw water and may serve as an effective and low-cost alternative to chlorine for household or other point-of-use water treatment.