TiO₂ nanoparticles exert an adverse effect on aquatic microbial communities

Area of Science:

• Environmental Science
• Ecotoxicology
• Microbial Ecology

Background:

• Titanium dioxide nanoparticles (n-TiO2) are prevalent in aquatic ecosystems due to widespread use.
• The ecotoxicological impact of n-TiO2 on freshwater microbial communities remains incompletely understood.

Purpose of the Study:

• To investigate the toxic effects of n-TiO2 on eukaryotic and prokaryotic microbial communities in freshwater.
• To elucidate the impact of n-TiO2 on microbial community structure, diversity, and function.

Main Methods:

• Monoculture growth inhibition assays comparing algae and cyanobacteria.
• Microcosm experiments assessing chlorophyll-a and phycocyanin content.
• Analysis of microbial community alpha and beta diversity.
• Co-occurrence network analysis to assess community stability.

Main Results:

• n-TiO2 exhibited greater inhibition on eukaryotic algae than cyanobacteria.
• Chlorophyll-a content decreased slightly, while phycocyanin content increased in microcosms.
• Eukaryotic community beta diversity increased, indicating compositional shifts, while alpha diversity remained unchanged.
• Prokaryotic community function was preserved, likely due to functional redundancy, but community composition was altered.
• n-TiO2 destabilized freshwater microbial communities, especially the eukaryotic component.

Conclusions:

• n-TiO2 poses a complex ecological risk to freshwater microbial communities.
• The destabilization of microbial communities by n-TiO2 highlights potential broader impacts on aquatic ecosystems.
• Emphasis on the rational utilization of n-TiO2 is necessary to minimize environmental risks.