Title

Nanospecific inhibition of pyoverdine siderophore production in Pseudomonas chlororaphis O6 by CuO nanoparticles

Document Type

Article

Journal/Book Title/Conference

Chemical Research in Toxicology

Volume

25

Issue

0893228X

Publication Date

1-1-2012

First Page

1066

Last Page

1074

DOI

10.1021/tx3000285

Abstract

CuO nanoparticles (NPs) exhibit dose-dependent toxicity to bacteria, whereas sublethal concentrations of these NPs change bacterial metabolism. Siderophores are model metabolites to study the impact of sublethal levels of metallic NPs on bacteria because they are involved in survival and interaction with other organisms and with metals. We report that a sublethal level of CuO NPs modify the production of the fluorescent siderophore pyoverdine (PVD) in a soil beneficial bacterium, Pseudomonas chlororaphis O6. The production of PVD was inhibited by CuO NPs but not by bulk CuO nor Cu ions at concentrations equivalent to those released from the NPs. The cell responses occurred despite the NPs forming near micrometer-sized aggregates. The CuO NPs reduced levels of periplasmic and secreted PVD and impaired expression from genes encoding proteins involved in PVD maturation in the periplasm and export through cell membranes. EDTA restored the fluorescence of PVD quenched by Cu ions but did not generate fluorescence with cultures of NP-challenged cells, confirming the absence of PVD. Consequently, depending on the bacterium, this nanoparticle-specific phenomenon mediating cellular reprogramming through effects on secondary metabolism could have an impact on critical environmental processes including bacterial pathogenicity. © 2012 American Chemical Society.

This document is currently not available here.

Share

COinS