Impact of an Engineered Copper-Titanium Dioxide Nanocomposite and Parent Substrates on the Bacteria Viability, Antioxidant Enzymes and Fatty Acid Profiling

Due to the systematic increase in the production of nanomaterials (NMs) and their applications in many areas of life, issues associated with their toxicity are inevitable. In particular, the performance of heterogeneous NMs, such as nanocomposites (NCs), is unpredictable as they may inherit the prop...

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Bibliographic Details
Main Authors: Oliwia Metryka, Daniel Wasilkowski, Anna Nowak, Małgorzata Adamczyk-Habrajska, Agnieszka Mrozik
Format: Article
Language:English
Published: MDPI AG 2020-11-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/21/23/9089
Description
Summary:Due to the systematic increase in the production of nanomaterials (NMs) and their applications in many areas of life, issues associated with their toxicity are inevitable. In particular, the performance of heterogeneous NMs, such as nanocomposites (NCs), is unpredictable as they may inherit the properties of their individual components. Therefore, the purpose of this work was to assess the biological activity of newly synthesized Cu/TiO<sub>2</sub>-NC and the parent nanoparticle substrates Cu-NPs and TiO<sub>2</sub>-NPs on the bacterial viability, antioxidant potential and fatty acid composition of the reference <i>Escherichia coli</i> and <i>Bacillus subtilis</i> strains. Based on the toxicological parameters, it was found that <i>B. subtilis</i> was more sensitive to NMs than <i>E. coli.</i> Furthermore, Cu/TiO<sub>2</sub>-NC and Cu-NPs had an opposite effect on both strains, while TiO<sub>2</sub>-NPs had a comparable mode of action. Simultaneously, the tested strains exhibited varied responses of the antioxidant enzymes after exposure to the NMs, with Cu-NPs having the strongest impact on their activity. The most considerable alternations in the fatty acid profiles were found after the bacteria were exposed to Cu/TiO<sub>2</sub>-NC and Cu-NPs. Microscopic images indicated distinct interactions of the NMs with the bacterial outer layers, especially in regard to <i>B. subtilis</i>. Cu/TiO<sub>2</sub>-NC generally proved to have less distinctive antimicrobial properties on <i>B. subtilis</i> than <i>E. coli</i> compared to its parent components. Presumably, the biocidal effects of the tested NMs can be attributed to the induction of oxidative stress, the release of metal ions and specific electrochemical interactions with the bacterial cells.
ISSN:1661-6596
1422-0067