Cu-doped TiO 2 nanoparticles enhance survival of Shewanella oneidensis MR-1 under Ultraviolet Light (UV) exposure

Bing Wu, Wei Qin Zhuang, Manoranjan Sahu, Pratim Biswas, Yinjie J. Tang

Research output: Contribution to journalArticlepeer-review

21 Scopus citations

Abstract

It has been shown that photocatalytic TiO 2 nanoparticles (NPs) can be used as an efficient anti-microbial agent under UV light due to generation of reactive oxygen species (ROS), while Shewanella oneidensis MR-1 is a metal-reducing bacterium highly susceptible to UV radiation. Interestingly, we found that the presence of Cu-doped TiO 2 NPs in the cultural medium dramatically increased the survival rates (based on colony-forming unit) of strain MR-1 by over 10,000-fold (incubation without shaking) and ~200 fold (incubation with shaking) after a 2-h exposure to UV light. Gene expression results (via qPCR measurement) indicated that the DNA repair gene recA in MR-1 was significantly induced by UV exposure (indicating cellular damage under UV stress), but the influence of NPs on recA expression was not statistically evident. Plausible explanations to NP attenuation of UV stresses are: 1. TiO 2 based NPs are capable of scattering and absorbing UV light and thus create a shading effect to protect MR-1 from UV radiation; 2. more importantly, Cu-doped TiO 2 NPs can co-agglomerate with MR-1 to form large flocs that improves cells' survival against the environmental stresses. This study improves our understanding of NP ecological impacts under natural solar radiation and provides useful insights to application of photocatalytic-NPs for bacterial disinfection.

Original languageEnglish (US)
Pages (from-to)4635-4639
Number of pages5
JournalScience of the Total Environment
Volume409
Issue number21
DOIs
StatePublished - Oct 1 2011
Externally publishedYes

Keywords

  • Absorb
  • Agglomerate
  • Disinfection
  • Flocs
  • RecA gene
  • Shaking

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Waste Management and Disposal
  • Pollution

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