Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China; The Fu Foundation School of Engineering and Applied Science, Columbia University, 500 W. 120th Street, New York, NY 10027, USA.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, People's Republic of China.
J Hazard Mater. 2023 Oct 15;460:132409. doi: 10.1016/j.jhazmat.2023.132409. Epub 2023 Aug 25.
Nanoplastics are ubiquitous in the natural environment, and their ecological risks have received considerable attention. Surface modification is common for nanoplastics and an essential factor affecting their toxicity. However, studies on the potential effects of nanoplastics and their surface-modified forms on functional communities in aquatic systems are still scarce. This study investigated the effects of nano-polystyrene (nPS), amino-modified nPS (nPS-NH), and carboxylated nPS (nPS-COOH) particles on sediment bacterial and fungal communities and their functions over a 60-day incubation period. The results showed that the fungal community was significantly inhibited by nPS-NH exposure, while the bacterial community diversity remained relatively stable in all nPS treatments. Proteobacteria and Ascomycota were the dominant phyla for the bacterial and fungal communities, respectively. Nitrification was inhibited in all nPS treatments, while denitrification was enhanced for nPS-NH and nPS-COOH treatments. The activity of four key denitrification enzymes (NAR, NIR, NOR, and NOS) was also significantly improved by nPS, resulting in increased nitrogen and nitrous oxide gas production, and decreased nitrate concentrations in the overlying water. This showed the total increased effect of nPS on the activity of denitrifiers. Our results suggest that surface modification significantly affects the effects of nPS on microbial communities and functions. The potential impacts of nPS on ecological functions should be elucidated with more attention.
纳米塑料在自然环境中无处不在，其生态风险受到了广泛关注。表面改性是纳米塑料的常见做法，也是影响其毒性的重要因素。然而，关于纳米塑料及其表面改性形式对水生系统功能群落潜在影响的研究仍然很少。本研究在 60 天的孵育期内，调查了纳米聚苯乙烯（nPS）、氨基改性 nPS（nPS-NH）和羧基化 nPS（nPS-COOH）颗粒对沉积物细菌和真菌群落及其功能的影响。结果表明，nPS-NH 暴露显著抑制了真菌群落，而在所有 nPS 处理中，细菌群落多样性保持相对稳定。变形菌门和子囊菌门分别是细菌和真菌群落的主要门。所有 nPS 处理均抑制了硝化作用，而 nPS-NH 和 nPS-COOH 处理则增强了反硝化作用。四种关键的反硝化酶（NAR、NIR、NOR 和 NOS）的活性也因 nPS 而显著提高，导致脱氮和亚硝酸盐气体的产生增加，以及上覆水中硝酸盐浓度降低。这表明 nPS 对反硝化菌活性的总增强效应。我们的研究结果表明，表面改性显著影响了 nPS 对微生物群落和功能的影响。应该更关注 nPS 对生态功能的潜在影响。
