Silver nanocrystallites: Facile biofabrication using Shewanella oneidensis, and an evaluation of their comparative toxicity on Gram-negative and Gram-positive bacteria

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Environmental Science & Technology

DOI:https://doi.org/10.1021/es903684r· OSTI ID:982725

Suresh, Anil K ^[1]; Wang, Wei ^[1]; Pelletier, Dale A ^[1]; Moon, Ji Won ^[1]; Gu, Baohua ^[1]; Mortensen, Ninell P ^[1]; Allison, David P ^[1]; Joy, David Charles ^[1]; Phelps, Tommy Joe ^[1]; Doktycz, Mitchel John ^[1]

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1. ORNL

Microorganisms have long been known to develop resistance to metal ions either by sequestering metals inside the cell or by effluxing them into the extracellular media. Here we report the biosynthesis of extracellular silver based single nanocrystallites of well-defined composition and homogeneous morphology utilizing the -proteobacterium, Shewanella oneidensis strain MR-1, upon incubation with an aqueous solution of silver nitrate. Further characterization of these particles revealed that the crystals consist of small, reasonably monodispersed spheres in the size range 2 11 nm (with an average of 4 1.5 nm). The bactericidal effect of these biologically synthesized silver nanoparticles (biogenic-Ag) are compared to similar chemically synthesized nanoparticles (colloidal silver [colloidal-Ag] and oleate capped silver [oleate-Ag]). The determination of the bactericidal effect of these different silver nanoparticles was assessed using both Gram-negative (E. coli) and Gram-positive (B. subtilis) bacteria and based on the diameter of the inhibition zone in disc diffusion tests, minimum inhibitory concentrations, Live/Dead staining assays, and atomic force microscopy. From a toxicity perspective, a clear synthesis procedure, and a surface coat- and strain-dependent inhibition were observed for silver nanoparticles. Biogenic-Ag was found to be of higher toxicity when compared to colloidal-Ag for both E. coli and B. subtilis. E. coli was found to be more resistant to either of these nanoparticles than B. subtilis. In contrast, Oleate-Ag was not toxic to either of the bacteria. These findings have important implications for the potential uses of Ag nanomaterials and for their fate in biological and environmental systems.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 982725
• Journal Information: Environmental Science & Technology, Journal Name: Environmental Science & Technology Journal Issue: 13 Vol. 44; ISSN 1520-5851; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AQUEOUS SOLUTIONS
ATOMIC FORCE MICROSCOPY
BACTERIA
BIOSYNTHESIS
DIFFUSION
EVALUATION
INCUBATION
MICROORGANISMS
MORPHOLOGY
SILVER
SILVER NITRATES
STRAINS
SYNTHESIS
TOXICITY