title: Involvement of radical species in inactivation of Vibrio parahaemolyticus in saline solutions by direct-current electric treatment.
abstract: The effect of pulsed low-direct-current (DC) electric treatment on the viability of Vibrio parahaemolyticus in artificial seawater and 3.0% (w/v) NaCl solution was studied as a function of available chlorine (AC) concentration. The amount of AC generated during the DC electric treatment increased in proportion to the amount of passed DC. The survival fraction of V. parahaemolyticus cells decreased depending on AC concentration. When the generated AC components were completely reduced in the presence of sufficient sodium thiosulfate, no inactivation of V. parahaemolyticus in the NaCl solution was observed during the DC electric treatment. Based on the AC concentration, the inactivation efficacies of the DC electric treatment of the seawater and NaCl solution were approximately 4-fold and 30-fold that of the exogenous addition of sodium hypochlorite, respectively. Fluorometric analysis using 2-[6-(4'-hydroxy)phenoxy-3H-xanthen-3-on-9-yl]benzoic acid showed that the generation of highly reactive radical species such as hydroxyl radical in the seawater and NaCl solution occurred during the DC electric treatment. The amount of generated radical species depended on the amount of passed DC. It is concluded that pulsed low-DC electric treatment of saline solutions exerts superior inactivation efficacy against V. parahaemolyticus to sodium hypochlorite owing to the generation of radical species.
authors.affiliation: Industrial Technology Center of Okayama Prefecture, 5301 Haga, Okayama 701-1296, Japan.
authors.forename: Hiromi
authors.initials: H
authors.lastname: Urano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ishikawa
authors.forename: Satoshi
authors.initials: S
authors.lastname: Fukuzaki
mesh_terms: D004560:Electricity; D005511:Food Handling; D017665:Hydroxyl Radical; D017382:Reactive Oxygen Species; D017747:Seafood / Q000382:microbiology*; D012623:Seawater; D012965:Sodium Chloride / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000494:pharmacology; D013885:Thiosulfates / Q000494:pharmacology; D014736:Vibrio parahaemolyticus / Q000187:drug effects / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D013885:Thiosulfates; D017665:Hydroxyl Radical; D012965:Sodium Chloride; D012973:Sodium Hypochlorite; C017717:sodium thiosulfate