title: Comparing TiO2photocatalysis and UV-C radiation for inactivation and mutant formation of Salmonella typhimurium TA102.
abstract: Salmonellosis is one of the most common causes of foodborne bacterial human disease worldwide, and the emergence of multidrug-resistant (MDR) strains of Salmonella enterica serovar Typhimurium (S. typhimurium) was associated to the incidence of invasive salmonellosis. The objective of the present work was to investigate the effects of the TiO2photocatalysis process in terms of both bacteria inactivation and the emergence of mutants, on S. typhimurium TA102 water suspensions. The TiO2photocatalysis was compared with a conventional disinfection process such as UV-C radiation. In spite of the faster bacterial inactivation obtained in UV-C disinfection experiments (45, 15, and 10 min for total inactivation for initial cell density 109, 108, and 107CFU mL-1, respectively), photocatalytic disinfection (60, 30, and 15 min) was more energy efficient because of a lower energy requirement (2-20 mWs cm-2) compared to the UV-C disinfection process (5-30 mWs cm-2). During the photocatalytic experiments, the mutation frequency increased up to 1648-fold compared to background level for a 108CFU mL-1initial bacterial density, and mutants were inactivated after 1-10-min treatment, depending on initial bacterial cell density. In UV-C disinfection experiments, the mutation frequency increased up to 2181-fold for a 108CFU mL-1initial bacterial cell density, and UV-C doses in the range of 0.5-4.8 mWs cm-2were necessary to decrease mutation frequency. In conclusion, both disinfection processes were effective in the inactivation of S. typhimurium cells, and mutants released into the environment can be avoided if cells are effectively inactivated.
authors: Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, SA, Italy.
authors: Antonino
authors: A
authors: Fiorentino
authors: Department of Civil Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084, Fisciano, SA, Italy. l.rizzo@unisa.it.
authors: Luigi
authors: http://orcid.org/0000-0003-1449-9116
authors: L
authors: Rizzo
authors: CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.|Université de Lorraine, LCPME, UMR 7564, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.
authors: Hélène
authors: H
authors: Guilloteau
authors: CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.|Université de Lorraine, LCPME, UMR 7564, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.
authors: Xavier
authors: X
authors: Bellanger
authors: CNRS, Laboratoire de Chimie Physique et Microbiologie pour l'Environnement (LCPME), UMR 7564, Institut Jean Barriol, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.|Université de Lorraine, LCPME, UMR 7564, 15 Avenue du Charmois, 54500, Vandoeuvre-lès-Nancy, France.
authors: Christophe
authors: C
authors: Merlin
mesh_terms: D004203:Disinfection / Q000379:methods; D016296:Mutagenesis / Q000187:drug effects / Q000528:radiation effects; D012486:Salmonella typhimurium / Q000187:drug effects* / Q000528:radiation effects*; D014025:Titanium / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: C009495:titanium dioxide; D014025:Titanium
keywords: Advanced oxidation processes; Ames test; Mutagenicity; Salmonella typhimurium; Water disinfection