Understanding the antimicrobial mechanism of TiO₂-based nanocomposite films in a pathogenic bacterium

Sci Rep. 2014 Feb 19:4:4134. doi: 10.1038/srep04134.


Titania (TiO₂)-based nanocomposites subjected to light excitation are remarkably effective in eliciting microbial death. However, the mechanism by which these materials induce microbial death and the effects that they have on microbes are poorly understood. Here, we assess the low dose radical-mediated TiO₂ photocatalytic action of such nanocomposites and evaluate the genome/proteome-wide expression profiles of Pseudomonas aeruginosa PAO1 cells after two minutes of intervention. The results indicate that the impact on the gene-wide flux distribution and metabolism is moderate in the analysed time span. Rather, the photocatalytic action triggers the decreased expression of a large array of genes/proteins specific for regulatory, signalling and growth functions in parallel with subsequent selective effects on ion homeostasis, coenzyme-independent respiration and cell wall structure. The present work provides the first solid foundation for the biocidal action of titania and may have an impact on the design of highly active photobiocidal nanomaterials.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Infective Agents / chemistry
  • Anti-Infective Agents / pharmacology*
  • Bacterial Proteins / metabolism
  • Catalysis
  • Electron Spin Resonance Spectroscopy
  • Nanocomposites / chemistry
  • Nanocomposites / toxicity*
  • Nanocomposites / ultrastructure
  • Proteomics
  • Pseudomonas aeruginosa / drug effects*
  • Pseudomonas aeruginosa / metabolism
  • Pseudomonas aeruginosa / radiation effects
  • Titanium / chemistry*
  • Transcriptome / drug effects
  • Transcriptome / radiation effects
  • Ultraviolet Rays


  • Anti-Infective Agents
  • Bacterial Proteins
  • titanium dioxide
  • Titanium