Extracellular conversion of silver ions into silver nanoparticles by protozoan Tetrahymena thermophila

Juganson, Katre; Mortimer, Monika; Ivask, Angela; Kasemets, Kaja; Kahru, Anne

doi:10.1039/c2em30731f

Scientific article

English

Extracellular conversion of silver ions into silver nanoparticles by protozoan Tetrahymena thermophila

Contributors

Juganson, Katre; Mortimer, Monika; Ivask, Angela; Kasemets, Kaja; Kahru, Anne

Published in

Environmental science. Processes & impacts, vol. 15, no. 1, p. 244-250

Publication date

2013

Abstract

In the current study, cell-free exudates of the ciliated protozoan Tetrahymena thermophila were shown to progressively convert silver nitrate to silver nanoparticles (Ag NPs) under illumination at ambient temperature. The formation of Ag NPs in the reaction mixture was evidenced by gradual colour changes, appearance of a specific absorbance peak (420–450 nm) and visualization using scanning electron microscopy coupled to an energy-dispersive X-ray spectrometer. After 2 h of incubation the mean hydrodynamic size of the Ag NPs was 70 nm. Seven days of incubation resulted in larger agglomerates and a significant decrease in silver toxicity to T. thermophila, accompanied by about 100-fold reduction in the silver ion concentration. Protein analysis indicated an extensive extracellular protein binding by the Ag NPs formed in the protozoan exudates. As protozoa are important components in wastewater treatment, their ability to sequester silver ions into a less bioavailable and less toxic form of silver (e.g. NPs) may be one of the adaption mechanisms of ciliate survival in contaminated environments.

UNIGE affiliation entities

Not a UNIGE publication

Citation (ISO format)

JUGANSON, Katre et al. Extracellular conversion of silver ions into silver nanoparticles by protozoan Tetrahymena thermophila. In: Environmental science. Processes & impacts, 2013, vol. 15, n° 1, p. 244–250. doi: 10.1039/c2em30731f

Article (Published version)

Identifiers

PID : unige:24664
DOI : 10.1039/c2em30731f

Additional URL for this publication

http://xlink.rsc.org/?DOI=c2em30731f

Journal ISSN

2050-7887

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Creation

12/12/2012 14:58:00

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12/12/2012 14:58:00

Update

14/03/2023 17:47:30

Status update

14/03/2023 17:47:30

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30/10/2024 08:04:21

Extracellular conversion of silver ions into silver nanoparticles by protozoan Tetrahymena thermophila

Contributors

Published in

Publication date

Abstract

UNIGE affiliation entities

Citation (ISO format)

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Additional URL for this publication

Journal ISSN

Technical informations

Creation

First validation

Update

Status update

Last indexation