School of Engineering, China Pharmaceutical University, Nanjing 210009, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China.
Sci Total Environ. 2023 Dec 15;904:166825. doi: 10.1016/j.scitotenv.2023.166825. Epub 2023 Sep 4.
With the increasing synthesis and application of carbon quantum dots (CQDs), their prevalence as pollution in water environments has increased. However, the toxic effects of CQDs on aquatic organisms are unclear, and their environmental safety must be evaluated. Herein, Daphnia magna was used as a model organism to explore the developmental toxicity of CQDs under a full life-cycle exposure. It was found that the feeding rate and offing number of D. magna decreased with increasing CQD concentration, and the body length of D. magna showed a trend of first increasing and then decreasing. These results indicated that long-term exposure to CQDs has evident toxic effects on D. magna development. Symbiosis analysis showed that the composition of the symbiotic microbial community of D. magna was disturbed by CQDs. The abundance of microorganisms involved in the immune response of D. magna such as Rhodobacter, decreased; those involved in the inflammation such as Gemmobacter, increased; and those involved in the nitrogen cycle, such as Hydrogenophaga and Paracoccus, decreased. When D. magna was subjected to environmental pressure, host-microflora interactive immune regulation was induced. The abundance of probiotics in D. magna, such as Rhodococcus, increased in response to environmental pressure. The results of KEGG function prediction showed that the abundance of symbiotic microorganisms involved in energy absorption and metabolism was affected by CQDs. In addition, the correlation analysis showed that there was a correlation between the changes in the symbiotic microbial community and the damage to D. magna after exposure to CQDs. Thus, it is appealed that as a potential environmental pollutant, CQDs have aquatic environmental risks, and their safe application deserves attention.
随着碳量子点（CQDs）的日益合成和应用，其在水环境中作为污染物的出现频率有所增加。然而，CQDs 对水生生物的毒性作用尚不清楚，必须对其环境安全性进行评估。在此，以大型溞（Daphnia magna）为模型生物，在全生命周期暴露下研究 CQDs 的发育毒性。结果发现，随着 CQD 浓度的增加，大型溞的摄食率和产卵数下降，而大型溞的体长呈现先增加后减少的趋势。这些结果表明，长期暴露于 CQDs 对大型溞的发育具有明显的毒性作用。共生分析表明，CQDs 干扰了大型溞共生微生物群落的组成。与大型溞免疫反应相关的微生物丰度下降，如 Rhodobacter；与炎症相关的微生物丰度增加，如 Gemmobacter；与氮循环相关的微生物丰度下降，如 Hydrogenophaga 和 Paracoccus。当大型溞受到环境压力时，会诱导宿主-微生物互作免疫调节。宿主中 Rhodococcus 等益生菌的丰度增加，以应对环境压力。KEGG 功能预测结果表明，CQDs 影响了共生微生物参与能量吸收和代谢的丰度。此外，相关分析表明，暴露于 CQDs 后，共生微生物群落的变化与大型溞的损伤之间存在相关性。因此，呼吁将 CQDs 作为一种潜在的环境污染物，其具有水生环境风险，其安全应用值得关注。
