The Response of Pseudomonas aeruginosa PAO1 to UV-activated Titanium Dioxide/Silica Nanotubes

Abstract

Pseudomonas aeruginosa is a bacterium of high clinical and biotechnological importance thanks to its high adaptability to environmental conditions. The increasing incidence of antibiotic-resistant strains has created a need for alternative methods to increase the chance of recovery in infected patients. Various nanomaterials have the potential to be used for this purpose. Therefore, we aimed to study the physiological response of P. aeruginosa PAO1 to titanium dioxide/silica nanotubes. The results suggest that UV light-irradiated nanomaterial triggers strong agglomeration in the studied bacteria that was confirmed by microscopy, spectrophotometry, and flow cytometry. The effect was diminished when the nanomaterial was applied without initial irradiation, with UV light indicating that the creation of reactive oxygen species could play a role in this phenomenon. The nanocomposite also affected biofilm formation ability. Even though the biomass of biofilms was comparable, the viability of cells in biofilms was upregulated in 48-hour biofilms. Furthermore, from six selected genes, the mexA coding efflux pump was upregulated, which could be associated with an interaction with TiO2. The results show that titanium dioxide/silica nanotubes may alter the physiological and metabolic functions of P. aeruginosa PAO1.

Basic physiology of Pseudomonas aeruginosa contacted with carbon nanocomposites

“…4, in the population's growth curve co-incubated with TiO 2 . It was the probable cause for the delay in entering the logarithmic growth phase, similarly to phenomena described for silica nanotubes (Augustyniak et al 2020a).…”

“…However, if these agglomerates have not been firmly attached to the forming biofilm, they could be washed out during the staining procedure (Merritt et al 2015). The agglomeration of pseudomonads promoted by nanomaterials has been previously described for carbon nanotubes and silica nanotubes (Ma et al 2010;Augustyniak et al 2020a). In the current studies, signs of such aggregation can be found in Fig.…”

“…While these microorganisms are good models for comparative studies regarding the antimicrobial activity of a compound, their value for biotechnological studies can be surpassed by other microorganisms. For that reason, the inclusion of Pseudomonas aeruginosa and other pseudomonads was also proposed to serve as additional models that have high medical and biotechnological significance (Augustyniak et al 2020a;Roszak et al 2021). This non-fermenting rod-shaped bacterium expresses high adaptability to the surrounding environment and is ubiquitous in soil, water, and hospital wards (Palleroni 2015).…”

Assessment of physiological responses of bacteria to chlorine and UV disinfection using a plate count method, flow cytometry and viability PCR

“…One possible explanation for this result could be that UV exposure might trigger strong agglomeration of P . aeruginosa (Augustyniak et al, 2020), leading to cells being less susceptible than E . coli to the UV doses applied.…”

Investigating the release of ZnO nanoparticles from cement mortars on microbiological models

“…The disruption of microbiota can influence cause, e.g., interruptions in the cycles of elements (sulfur, phosphorus, nitrogen, and carbon) (Philippot et al 2013). On the other hand, nanomaterials' admixtures may be used to change microorganisms' behavior that should be further studied to use these phenomena in applied sciences (e.g., biotechnology) (Augustyniak et al 2016(Augustyniak et al , 2020a.…”