Organic matter excreted by the protozoan Tetrahymena thermophila and its effects on the bioaccumulation of nanoparticles.

Autor: Zhang KD; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Zhang HJ; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Song JL; Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China., Wang XL; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Pan W; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Wang M; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Huang B; Jiangsu Open Laboratory of Major Scientific Instrument and Equipment, Jiangsu Province Engineering Research Center of Environmental Risk Prevention and Emergency Response Technology, School of Environment, Nanjing Normal University, Nanjing 210023, China., Yang L; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China., Miao AJ; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu Province 210023, China. Electronic address: miaoaj@nju.edu.cn.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2024 Dec 05; Vol. 480, pp. 135972. Date of Electronic Publication: 2024 Sep 26.
DOI: 10.1016/j.jhazmat.2024.135972
Abstrakt: Although organic matter (exudate) excreted by aquatic organisms is an important component of dissolved organic matter (DOM) in the natural environment, its potential effects on the bioaccumulation of nanoparticles (NPs) remain unclear. In the present study, we examined the effects of the exudates from the protozoan Tetrahymena thermophila on the bioaccumulation (including uptake and cell surface adsorption) of iron oxide (Fe 2 O 3 , polyacrylate coated) and silica (SiO 2 ) NPs in T. thermophila. The exudates were mostly (93.6 %, in carbon) composed of < 1-kDa molecules (e.g., lipids). When the exudates were mixed with the NPs, significant adsorption occurred on SiO 2 NPs but not on Fe 2 O 3 NPs. Independent of their adsorption by the NPs, the exudates significantly inhibited the bioaccumulation of both SiO 2 NPs and Fe 2 O 3 NPs by T. thermophila. This inhibitory effect was shown to be mainly due to their inhibition of NP adsorption on the cell surface. By contrast, the exudates had negligible effects on the uptake of either NP type, most likely due to their low molecular weight. Since DOM in the aquatic environment is dominated by molecules < 1 kDa, the potential effects of low-molecular-weight DOM, such as exudates from aquatic organisms, on the bioaccumulation of NPs merits greater attention. ENVIRONMENTAL IMPLICATION: Nanoparticles (NPs) are hazardous materials widespread in the natural environment. Previous studies showed that dissolved organic matter (DOM) in aquatic environments determine the environmental behavior and ecological effects of NPs. Although organic matter (exudate) excreted by aquatic organisms is an important component of DOM, its potential effects on the bioaccumulation of NPs remain unclear. In the present study, we found that the exudates inhibited the cell-surface adsorption of NPs but had no effects on NP uptake, as different from the well-known effects of DOM on NP bioaccumulation. This finding merits attention during evaluations of the environmental risks of NPs.
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.
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Databáze: MEDLINE
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