Ti/TiO₂ nanotubes enhance Mycobacterium fortuitum, Mycobacterium chelonae and Mycobacterium abscessus inactivation in water

Abstract

BACKGROUND Rapid‐growing mycobacteria are difficult to eradicate using common disinfection practices, when compared with coliforms. They are resistant to chlorination, which is commonly used in swimming pool and drinking water treatment. They also resist treatment with glutaraldehyde (GA), benzalkonium chloride, organomercury compounds, chlorohexidine, and even autoclavation. So, the present work describes the development of a new treatment method for Mycobacterium disinfection based on phoelectrocatalytical oxidation at Ti/TiO2 nanotubes electrodes, which could be a promising alternative for its inactivation in a short treatment time. RESULTS Nanotubular TiO2 was grown on Ti surface using electrochemical anodization in fluoride medium and applied to photoelectrocatalytic inactivation of 103 CFU mL‐1 Mycobaterium fortuitum, M. chelonae, and M. abscessus, which was achieved after 3 min treatment. The metabolites released during cellular lysis were also degraded with 240 min of photoelectrocatalytical treatment, as monitored by mass spectroscopy measurements. Mineralization was greater than 70% under optimum conditions. The photoelectrocatalytic method gave better results than the photolytic and photocatalytic techniques. The method provided the most efficient mycobacterial inactivation and TOC removal rate, thus being the best to disinfect mycobacterium‐infected water. CONCLUSION Photoelectrodes based on Ti/TiO2 nanotubes prepared by electrochemical anodization are a powerful alternative to disinfect mycobacterium‐ contaminated water. © 2013 Society of Chemical Industry

Achievements and Trends in Photoelectrocatalysis: from Environmental to Energy Applications

“…The photoelectrocatalytic oxidation promoted the inactivation in 3 min of treatment and the complete degradation of mycolic acids and polysaccharides contained in the cell wall of mycobacteria after 30 min of treatment. The inactivation of Mycobacterium kansasii, Mycobacterium avium, Mycobacterium fortuitum, Mycobacterium chelonae, and Mycobacterium abscessus has been also reported [10,146,147] using Ag-TiO 2 NTs. For the mycobacteria concentration of 7.5×10 4 CFU mL −1 , total inactivation was achieved after 3 min of treatment.…”

The Pathway towards Photoelectrocatalytic Water Disinfection: Review and Prospects of a Powerful Sustainable Tool

“…The excellent inactivation ability of PEC for several species of mycobacteria has been confirmed by Zanoni's group in pure water. They disinfected aqueous solutions of M. kansasii and M. avium [22], M. smegmatis [58,84], M. fortuitum, M. chelonae, M. abscessus [85], and M. tuberculosis [86], using Ti|TiO 2 and Ti|TiO 2 -Ag NTs photoanodes under UVA or visible illumination. For instance, 250 mL of 5 × 10 8 CFU mL −1 M. kansasii or M. avium [22] and 7 × 10 4 CFU mL −1 M. smegmatis [58] in 0.05 M Na 2 SO 4 were treated with an undivided three-electrode tank reactor submitted to external illumination with a 125 W UVA lamp.…”

Advanced Oxidation Process Applied to Actinobacterium Disinfection

“…Mineralization was greater than 70% under optimum conditions. The photoelectrocatalytic method gave better results than the photolytic and photocatalytic techniques [76]. TiO 2 nanotubular array electrodes coated with 16% (w/w) Ag NPs (Ti/TiO 2 -Ag) have shown excellent performance in the disinfection of water containing Mycobacterium smegmatis [77].…”