title: Enhanced Inactivation of Escherichia coli and MS2 Coliphage by Cupric Ion in the Presence of Hydroxylamine: Dual Microbicidal Effects.
abstract: The inactivation of Escherichia coli and MS2 coliphage by Cu(II) is found to be significantly enhanced in the presence of hydroxylamine (HA). The addition of a small amount of HA (i.e., 5-20 μM) increased the inactivation efficacies of E. coli and MS2 coliphage by 5- to 100-fold, depending on the conditions. Dual effects were anticipated to enhance the biocidal activity of Cu(II) by the addition of HA, viz. (i) the accelerated reduction of Cu(II) into Cu(I) (a stronger biocide) and (ii) the production of reactive oxidants from the reaction of Cu(I) with dissolved oxygen (evidenced by the oxidative transformation of methanol into formaldehyde). Deaeration enhanced the inactivation of E. coli but slightly decreased the inactivation efficacy of MS2 coliphage. The addition of 10 μM hydrogen peroxide (H2O2) greatly enhanced the MS2 inactivation, whereas the same concentration of H2O2 did not significantly affect the inactivation efficacy of E. coli Observations collectively indicate that different biocidal actions lead to the inactivation of E. coli and MS2 coliphage. The toxicity of Cu(I) is dominantly responsible for the E. coli inactivation. However, for the MS2 coliphage inactivation, the oxidative damage induced by reactive oxidants is as important as the effect of Cu(I).
authors.affiliation: School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulju-gun, Ulsan, 689-798, Republic of Korea.
authors.forename: Hyung-Eun
authors.initials: HE
authors.lastname: Kim
authors.affiliation: Power Engineering Consulting Joint Stock Company 2 (PECC2) , 32 Ngo Thoi Nhiem str., Ward 7, District 3, Ho Chi Minh City, Vietnam.
authors.forename: Thuy T M
authors.initials: TT
authors.lastname: Nguyen
authors.affiliation: School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulju-gun, Ulsan, 689-798, Republic of Korea.
authors.forename: Hongshin
authors.initials: H
authors.lastname: Lee
authors.affiliation: School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST) , 50 UNIST-gil, Ulju-gun, Ulsan, 689-798, Republic of Korea.
authors.forename: Changha
authors.initials: C
authors.lastname: Lee
mesh_terms: D003300:Copper / Q000737:chemistry / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000187:drug effects*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D019811:Hydroxylamine / Q000494:pharmacology*; D017909:Levivirus / Q000187:drug effects*; D016877:Oxidants / Q000737:chemistry / Q000494:pharmacology; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D014871:Water Microbiology
chemical_list: D004202:Disinfectants; D016877:Oxidants; D019811:Hydroxylamine; D003300:Copper; D006861:Hydrogen Peroxide; D010100:Oxygen