Silver nanoparticle impact on bacterial growth: effect of pH, concentration, and organic matter

Julia Fabrega, Shona R. Fawcett, Joanna C. Renshaw, Jamie R. Lead

Research output: Contribution to journalArticle

578 Citations (Scopus)

Abstract

Silver nanoparticles (Ag NPs) are widely used as antibacterial agents. This antibacterial property carries with it a potential environmental risk once these NPs are discharged into the environment. This study investigated the impact on Pseudomonas fluorescens over a 24 h exposure of well characterized Ag NPs at pH values of 6-9, in the presence and absence of Suwannee River humic acids (SRHA). Ag NPs were characterized by size, aggregation, morphology, dissolution, and surface properties under all conditions. Solubility was low (less than 2%) for all Ag NP concentrations (2-2000 ppb) and under all conditions was less than 40 ppb (0.38 μM). SRHA caused a partial disaggregation of Ag NP aggregates by nanoscale film formation, with individual NPs stabilized by charge and entropically driven steric effects. Dissolved Ag reduced bacterial growth entirely at 2000 ppb (19 μM) under all conditions and adversely affected growth at 200 ppb (1.9 μM) under some conditions, indicating some toxicity. The Ag NPs showed similar toxicity at 2000 ppb (19 μM) in the absence of SRHA and at pH 9 only i.e. SRHA mitigated bactericidal action. Solubility and interactions with SRHA indicate that there was a specific nanoparticle effect, which could not be explained by the effect of dissolved Ag.

Original languageEnglish
Pages (from-to)7285-7290
Number of pages6
JournalEnvironmental Science and Technology
Volume43
Issue number19
Early online date8 Jun 2009
DOIs
Publication statusPublished - 1 Oct 2009

Keywords

  • silver nanoparticle impact
  • bacterial growth
  • pH concentration
  • organic matter
  • Ag NPs
  • antibacterial agents
  • environmental risk
  • Suwannee River humic acids
  • SRHA

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  • Projects

    Impacts of silver nanoparticles on planktonic and biofilm bacteria

    Renshaw, J., Lead, J. & Fabrega, J.

    1/10/051/10/08

    Project: Projects from Previous Employment

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