Comparative antibacterial activities of neutral electrolyzed oxidizing water and other chlorine-based sanitizers.
Abiodun D Ogunniyi, Catherine E Dandie, Sergio Ferro, Barbara Hall, Barbara Drigo, Gianluca Brunetti, Henrietta Venter, Baden Myers, Permal Deo, Erica Donner, Enzo Lombi
Author Information
Abiodun D Ogunniyi: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia. david.ogunniyi@unisa.edu.au. ORCID
Catherine E Dandie: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia.
Sergio Ferro: Ecas4 Australia Pty Ltd, 8/1 London Road, Mile End South, South Australia, Australia.
Barbara Hall: Plant Health and Biosecurity, SARDI, Adelaide, South Australia, Australia.
Barbara Drigo: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia.
Gianluca Brunetti: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia. ORCID
Henrietta Venter: School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia. ORCID
Baden Myers: Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, Mawson Lakes, South Australia, Australia.
Permal Deo: School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia.
Erica Donner: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia.
Enzo Lombi: Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, Australia. ORCID
There is increasing demand for safe and effective sanitizers for irrigation water disinfection to prevent transmission of foodborne pathogens to fresh produce. Here we compared the efficacy of pH-neutral electrolyzed oxidizing water (EOW), sodium hypochlorite (NaClO) and chlorine dioxide (ClO) against single and mixed populations of E. coli, Listeria and Salmonella under a range of pH and organic matter content. EOW treatment of the mixed bacterial suspension resulted in a dose-dependent (<1 mg/L free chlorine), rapid (<2 min) and effective (4-6 Log) reduction of the microbial load in water devoid of organic matter under the range of pH conditions tested (pH, 6.0, 7.0, 8.4 and 9.2). The efficacy of EOW containing 5 mg/L free chlorine was unaffected by increasing organic matter, and compared favourably with equivalent concentrations of NaClO and ClO. EOW at 20 mg/L free chlorine was more effective than NaClO and ClO in reducing bacterial populations in the presence of high (20-100 mg/L) dissolved organic carbon, and no regrowth or metabolic activity was observed for EOW-treated bacteria at this concentration upon reculturing in rich media. Thus, EOW is as effective or more effective than other common chlorine-based sanitizers for pathogen reduction in contaminated water. EOW's other characteristics, such as neutral pH and ease of handling, indicate its suitability for fresh produce sanitation.
