Effects of silver nanoparticles on bacterial activity in natural waters.
Environ Toxicol Chem
; 31(1): 122-30, 2012 Jan.
Article
en En
| MEDLINE
| ID: mdl-22012876
ABSTRACT
Silver nanoparticles (AgNPs) may be introduced into aquatic ecosystems because of their widespread use as antimicrobial agents. However, few studies have investigated the impacts of AgNPs on natural aquatic microbial activity in an environmentally relevant context. In this study, bacterioplankton were collected from nine aquatic habitats and exposed to six concentrations of carboxy-functionalized AgNP (ViveNano, 10-nm particle size, 20% Ag w/w) over 48 h. After 1 h of exposure, bacterial production and extracellular alkaline phosphatase affinity were significantly reduced in all AgNP-exposed samples. However, across a 48-h exposure, extracellular aminopeptidase affinity was not consistently impacted by AgNPs. After 48 h, bacterial production recovered by 40 to 250% at low AgNP nominal concentrations (0.05 and 0.1 mg/L) but remained inhibited at the two highest AgNP nominal concentrations (1 and 10 mg/L). In contrast, AgNO(3) additions between 0.01 to 2 mg Ag/L fully inhibited bacterial production over the 48-h exposure. At 48-h exposure, the lowest observed effective concentrations and average median effective concentration for bacterial production ranged from 8 to 66 and 15 to 276 µg Ag/L, respectively. Thus, in natural aquatic systems, AgNP concentrations in the nanogram per liter range are unlikely to negatively impact aquatic biogeochemical cycles. Instead, exposures in the low microgram per liter range would likely be required to negatively impact natural aquatic bacterioplankton processes.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plata
/
Bacterias
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Microbiología del Agua
/
Contaminantes Químicos del Agua
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Nanopartículas del Metal
Idioma:
En
Revista:
Environ Toxicol Chem
Año:
2012
Tipo del documento:
Article
País de afiliación:
Canadá