Impact of TiO₂ and ZnO nanoparticles on an aquatic microbial community: effect at environmentally relevant concentrations

Abstract

To investigate effects of engineered nanoparticles (ENPs) at environmentally relevant concentrations to aquatic microbial communities, TiO₂ at 700 µg/L and ZnO at 70 µg/L were spiked to river water samples either separately or combined. Compared to controls where no ENPs were added, the addition of TiO₂ ENPs alone at the tested concentration had no statistically significant effect on both the bacterial and eukaryotic communities. The presence of added ENPs: ZnO or ZnO + TiO₂ led to significant shift of the microbial community structure and genus distribution. This shift was more obvious for the bacteria than the eukaryotes. Based on results from single particle – inductively coupled plasma – mass spectrometry (SP-ICP-MS), all ENPs aggregated rapidly in water and resulted in much larger particles sizes than the original counterparts. “Dissolved” (including particles smaller than the size detection limits and dissolved ions) concentrations of Ti and Zn increased, too in treatment groups vs. the controls.

Keywords:

• Engineered TiO2 and ZnO nanoparticles
• microbial community
• single particle – inductively coupled plasma – mass spectrometry
• next generation DNA sequencing
• river water

Acknowledgements

The NexION 300/350 D ICP-MS was provided by PerkinElmer, Inc. The authors appreciate the support from University of Missouri Research Board. The authors also appreciate the meticulous review and constructive comments provided by the peer reviewers.

Disclosure statement

The authors report no conflicts of interest.