Investigation into the physiological state of Escherichia coliK 12 cells under the action of TiO2 nanoparticles in acidic conditions

• Published in: Nanotechnologies in Russia 2013, Vol.8 (9-10), p.678-683
• Main Author: Zhukova, L. V.
• Format: Article
• Language: English
• Subjects: Aggregates; Chemistry and Materials Science; Composition; Deactivation; Deionization; E coli; Fluorescent dyes; Industrial and Production Engineering; Irradiation; Machines; Manufacturing; Materials Science; Nanoparticles; Nanotechnology; Physiology; Processes; Staining; Titanium dioxide; Ultraviolet radiation
• ISSN: 1995-0780; 1995-0799
• DOI: 10.1134/S1995078013050169

The physiological state of E. coli K12 bacterial cells under the action of TiO 2 nanoparticles (0.04 g/L) was investigated with the method of staining by an acridine orange fluorescent dye in order to elucidate the mechanism of the antibacterial activity of nanoparticles. Experiments were performed in deionized water at initial pH 4.05–4.15, at which the surfaces of cells and nanoparticles carry opposite charges, without and with UV irradiation. The staining of the cells after incubation with TiO 2 nanoparticles showed that both in the absence and under the action of UV irradiation, inactive cells were detected only in the composition of aggregates formed in the process of incubation and predominantly in their inner part. Active cells were found mainly in the composition of small aggregates and on the surface of the large aggregates, as well as single cells. The results obtained in this study allow suggesting that the compression due to the mutual attraction of the cells coated with TiO 2 nanoparticles plays a significant role in the process of E. coli K12 cell inactivation.