Responses of a Soil Bacterium, Pseudomonas chlororaphis O6 to Commercial Metal Oxides Nanoparticles Compared With Responses to Metal Ions
Document Type
Article
Journal/Book Title/Conference
Environmental Pollution
Volume
159
Issue
2697491
Publication Date
1-1-2011
First Page
1749
Last Page
1756
Abstract
The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells' periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes. © 2011 Elsevier Ltd. All rights reserved.
Recommended Citation
Dimkpa, C.O., A. Calder, D.W. Britt, J.E. McLean, and A.J. Anderson. 2011. Responses of a soil bacterium, Pseudomonas chlororaphis O6 to commercial metal oxides nanoparticles compared with responses to metal ions. Environ. Pollution. 159:1749-1756.
