Time-dependent effects of ZnO nanoparticles on bacteria in an estuarine aquatic environment.
Sci Total Environ
; 698: 134298, 2020 Jan 01.
Article
in En
| MEDLINE
| ID: mdl-31505343
ABSTRACT
Many studies have examined the acute toxicity of nanoparticles (NPs) towards model bacteria. In this study, we report the time-dependent effects of ZnO NPs on native, selected Zn-resistant and dominant bacteria in estuarine waters. An initial inhibition of bacterial growth followed by a recovery at 24â¯h was observed, and this rebound phenomenon was particularly notable when the raw water samples were treated with relatively high ZnO NP concentrations (1 and 10â¯mg/L).By comparing the groups treated with Zn2+, Zn2+ was shown to largely explain the acute cytotoxic effect of ZnO NPs on bacteria in raw waters. Furthermore, similar to the native bacteria, especially the dominant bacteria, the viability of Escherichia coli (E. coli) decreased with the increasing treatments time and the concentrations of ZnO NPs in water with different salinities. Moreover, the expression of Zn-resistance genes including zntA and zntR in E. coli suggested that the Zn-resistance system in E. coli can be activated to defend against the stress of Zn2+ released from ZnO NPs, and salinity may promote this process in estuarine aquatic systems. Thus, the effect of ZnO NPs on bacteria in estuarine water bodies is likely determined by the synergistic effect of environmental salinity and dissolved Zn ions. As such, our findings are of high relevance and importance for understanding the ecological disturbances caused by anthropogenic NPs in estuarine environments.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacteria
/
Water Pollutants, Chemical
/
Zinc Oxide
/
Metal Nanoparticles
Type of study:
Prognostic_studies
Language:
En
Journal:
Sci Total Environ
Year:
2020
Document type:
Article
Affiliation country: