# Effect of Ozonized Water against Pathogenic Bacteria and Filamentous Fungi on Stainless Steel  
[PERSON]  
1 Microbiology--Quality, Safety and Pre-Industrialization Area, SSICA, Stazione Sperimentale per l'Industria delle Conserve Alimentaria--Fondazione di Ricerca, Viale F. Tanara, 31/A, 43121 Parma, Italy; 12 Dipartimento di Scienze Chimiche, Della vite e Della Sostenibilita Ambientale, Parco Area delle Scienze, Universita degli Studi di Parma, 31/A, 43124 Parma, Italy 2  
[PERSON]  
2 Dipartimento di Scienze Chimiche, Della vite e Della Sostenibilita Ambientale, Parco Area delle Scienze, Universita degli Studi di Parma, 31/A, 43124 Parma, Italy 2  
[PERSON]  
1 Microbiology--Quality, Safety and Pre-Industrialization Area, SSICA, Stazione Sperimentale per l'Industria delle Conserve Alimentaria--Fondazione di Ricerca, Viale F. Tanara, 31/A, 43121 Parma, Italy; 1  
[PERSON]  
3 Environment--Sustainability and Valorization Area, SSICA, Stazione Sperimentale per l'Industria delle Conserve Alimentaria--Fondazione di Ricerca, Viale F. Tanara, 31/A, 43121 Parma, Italy; 3  
[PERSON]  
1 Microbiology--Quality, Safety and Pre-Industrialization Area, SSICA, Stazione Sperimentale per l'Industria delle Conserve Alimentaria--Fondazione di Ricerca, Viale F. Tanara, 31/A, 43121 Parma, Italy; 1  
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Footnote 2: [[https://www.mdpi.com/journals/pdfs/](https://www.mdpi.com/journals/pdfs/)]([https://www.mdpi.com/journals/pdfs/](https://www.mdpi.com/journals/pdfs/))  
Aqueous ozone has been known for over a hundred years as a sanitizing agent. At the beginning, it was used for the sanitization of drinking water, whereas in the last decades its usage has been extended to a wide range of activities like swimming pool disinfection, food industry processing, clinical medical applications, and even industrial laundry operations [5,6]. Nowadays, food industries use aqueous ozone to reduce microbial loads on wastewater [7,8] and a wide range of foods such as fresh fruits [9, 10, 11], dried fruits [12], nuts [13], vegetables [14, 15, 16], and meats [17,18]. Its use concentrations are usually up to 10 ppm for application times varying from some minutes to one hour, alone or in combination with other sanitizing methods. Concerning this aspect, the UV-C light is the most common coupling [8,19], even if the use of aqueous ozone in combination with chlorine [20], organic acids [21,22], or hydrogen peroxide [7] has also been registered. Similarly, its use as a sanitizing agent on different types of surfaces has been deeply investigated. The papers concerning this topic were referred to as food-grade steel [23, 24, 25, 26, 27], multi-laminated food packaging [28], polyethylene terephthalalate [29], polystyrene [30], and polypropylene [31]. [PERSON] and [PERSON] [32] even tested the effectiveness of ozonized water up to 30 ppm in inactivating microbes in a food-packaging film sterilizing machine. Unfortunately, most of the works supply punctual data without assessing the inactivation kinetics of the studied microorganisms; only the paper by [PERSON] et al. [33] assessed the D-value of the pathogen _Pseudomonas aeruginosa_ on glass, ceramics, and medical industry-related plastics. In addition to this, filamentous fungi were not included in the group of investigated microorganisms when aqueous ozone was tested on materials, even if they can contaminate working surfaces and machinery interiors as well as bacteria. Therefore, the aim of this paper was the assessment of the resistance to aqueous ozone of two pathogenic bacteria, _Listeria monocytogenes_ and _Salmonella_ spp., and of two airborne food-spoiling fungi, _Hypophictia burtonii_ and _Penicillium noricum_, inoculated on stainless steel (SS) and treated in static conditions.