Antibacterial Effect of Aluminum Surfaces Untreated and Treated with a Special Anodizing Based on Titanium Oxide Approved for Food Contact
by
, , , , ,
Alessandro Di Cerbo
1,*,†
,
Andrea Mescola
2,†
,
Ramona Iseppi
3
,
Roberto Canton
4
,
Giacomo Rossi
1
,
Roberta Stocchi
1, 
Anna Rita Loschi
1,
Andrea Alessandrini
2,5, 
Stefano Rea
1 and
Carla Sabia
3
1
School of Biosciences and Veterinary Medicine, University of Camerino, 62024 Matelica, Italy
2
CNR-Nanoscience Institute-S3, 41125 Modena, Italy
3
Department of Life Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
4
Moma Nanotech Srl, 20861 Brugherio, Italy
5
Department of Physics, Informatics e Mathematics, University of Modena and Reggio Emilia, 41125 Modena, Italy
*
Author to whom correspondence should be addressed.
†
These authors contributed equally.
Biology 2020, 9(12), 456; https://doi.org/10.3390/biology9120456
Submission received: 5 November 2020
/
Revised: 5 December 2020
/
Accepted: 8 December 2020
/
Published: 10 December 2020
(This article belongs to the Special Issue Listeria Monocytogenes in Foods: from Resistance Mechanisms to Development of Novel Protective Strategies)
Simple Summary
We firstly described the bacteriostatic activity of aluminum surfaces with three different large-scale roughness against both Gram-negative and Gram-positive bacteria, and the bactericidal activity of three different sanitizing treatments performed on each roughness. Then, we described the bactericidal activity of the same surfaces treated with a special anodizing based on titanium oxide regardless of sanitizing agents and roughness.
Abstract
One of the main concerns of the food industry is microbial adhesion to food contact surfaces and consequent contamination. We evaluated the potential bacteriostatic/bactericidal efficacy of aluminum surfaces with different large-scale roughness (0.25, 0.5 and 1 μm) before and after the surface treatment with a special anodizing based on titanium oxide nanotechnology (DURALTI®) and after 3 different sanitizing treatments, e.g., UV, alcohol and a natural product named Gold lotion. Four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) bacteria were screened. As far as concerns aluminum surfaces without nanotechnology surface treatment, an overall bacteriostatic effect was observed for all strains with respect to the initial inoculum that was 106 CFU/mL. Conversely, an overall bactericidal effect was observed both for Gram-negative and -positive bacteria on DURALTI®-treated aluminum disks, regardless of roughness and sanitizing treatment. These results are innovative in terms of the great potential of the antibacterial activity of nanotechnologically treated food contact surfaces and their combination with some sanitizing agents that might be exploited in the food industry.
