Work

Impact of TiO2 Nanoparticles on Growth, Biofilm Formation, and Flavin Secretion in Shewanella oneidensis

Year: 2013

Type: article

Abstract: Understanding of nanoparticle impacts on critical bacteria functions allows us to gain a mechanistic understanding of toxicity and guides us toward design rules for creating safe nanomaterials. Herein, biofilm formation, a general bacteria function, and riboflavin secretion, a species-specific function, were monitored in Shewanella oneidensis, a metal reducing bacterium, following exposure to a variety of TiO2 nanoparticle types (synthesized, Aeroxide P25, and T-Eco). Transmission electron microscopy (TEM) images show that dosed nanoparticles are in close proximity to the bacteria, but they are not internalized. Using quartz crystal microbalance (QCM), it was revealed that S. oneidensis biofilm formation is slowed in the presence of nanoparticles. Though S. oneidensis grows more slowly in the presence of TiO2 nanoparticles, riboflavin secretion, a function related to the S. oneidensis metal reducing capacity, was increased significantly in a nanoparticle dose-dependent manner. Both changes in biofilm formation and riboflavin secretion are supported by changes in gene expression in nanoparticle-exposed S. oneidensis. This broad study of bacterial nanotoxicity, including use of sensitive analytical tools for functional assessments of biofilm formation, riboflavin secretion, and gene expression, has implications for total ecosystem health as the use of engineered nanoparticles grows.

Source: Analytical Chemistry

DOI: 10.1021/ac400486u

Authors: Melissa A. Maurer-Jones, Ian L. Gunsolus, Ben M. Meyer, Cole J. Christenson, Christy L. Haynes

Institution: University of Minnesota

Language: English

Topic: Nanoparticles: synthesis and applications

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green