title: The short-term toxic effects of TiO₂nanoparticles toward bacteria through viability, cellular respiration, and lipid peroxidation.
abstract: To better understand the potential impacts of metal oxide nanoparticles (NPs) on Gram(+) Bacillus subtilis and Gram(-) Escherichia coli (K12) bacteria, eight different nanosized titanium dioxide (TiO2) suspensions with five different concentrations were used. Water quality parameters (pH, temperature, and ionic strength), light sources, and light intensities were also changed to achieve different environmental conditions. The photosensitive TiO2 NPs were found to be harmful to varying degrees under ambient conditions, with antibacterial activity increasing with primary particle sizes from 16 to 20 nm. The presence of light was a significant factor under most conditions tested, presumably due to its role in promoting generation of reactive oxygen species (ROS). However, bacterial growth inhibition was also observed under dark conditions and different water quality parameters, indicating that undetermined mechanisms additional to photocatalytic ROS production were responsible for toxicity. The results also indicated that nano-TiO2 particles in the absence and the presence of photoactivation induced lipid peroxidation and cellular respiration disruption.
authors.affiliation: Department of Environmental Engineering, Akdeniz University, Antalya, 07058, Turkey. ayerdem@akdeniz.edu.tr.|Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, 19716, USA. ayerdem@akdeniz.edu.tr.
authors.forename: Ayca
authors.initials: A
authors.lastname: Erdem
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, 19716, USA.
authors.forename: David
authors.initials: D
authors.lastname: Metzler
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, 19716, USA.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Cha
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE, 19716, USA.
authors.forename: C P
authors.initials: CP
authors.lastname: Huang
mesh_terms: D001412:Bacillus subtilis / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D048168:Escherichia coli K12 / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D008027:Light; D015227:Lipid Peroxidation / Q000187:drug effects*; D053768:Metal Nanoparticles / Q000737:chemistry*; D050296:Microbial Viability / Q000187:drug effects*; D010316:Particle Size; D017382:Reactive Oxygen Species / Q000633:toxicity; D013997:Time Factors; D014025:Titanium / Q000737:chemistry / Q000528:radiation effects / Q000633:toxicity*
chemical_list: D017382:Reactive Oxygen Species; C009495:titanium dioxide; D014025:Titanium
keywords: B. subtilis; Cell inactivation; Cellular respiration disruption; E. coli; Lipid peroxidation; TiO2 nanoparticles