Search

Titanium dioxide nanoparticle (n-TiO 2 ) is a widely used nanomaterial, which is inevitably released as a residue into aquatic ecosystems during material production and usage. However, the effects of n-TiO 2 on aquatic microbial communities have not been completely elucidated. This study examined the toxic effects of n-TiO 2 on eukaryotic and prokaryotic microbial communities in freshwater environments. We determined that n-TiO 2 had a greater inhibitory effect on the growth of eukaryotic algae than cyanobacteria in monocultures. A similar phenomenon was observed in a microcosm experiment, revealing that n-TiO 2 slightly reduced the content of chlorophyll-a but evidently increased the phycocyanin content. Moreover, the alpha diversity of the eukaryotic community was not affected, whereas its beta diversity increased with exposure to n-TiO 2 . Although n-TiO 2 altered the composition of freshwater microbial communities, it did not change the functions of the prokaryotic community, which might be attributed to the functional redundancy of microbiota. Co-occurrence network analysis indicated that n-TiO 2 destabilized the freshwater community, especially the eukaryotic community, and potentially disturbed the aquatic ecosystem. Our study revealed that the ecological risk of n-TiO 2 on aquatic microbial communities is complex; hence, rational utilization of n-TiO 2 should be emphasized., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)