Preferential adsorption of medium molecular weight proteins in extracellular polymeric substance alleviates toxicity of small-sized microplastics to Skeletonema costatum.

Autor: Li X; School of Life and Health Sciences, Hainan University, Haikou 570228, China; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, Tianjin International Joint Research Center for Environmental Biogeochemical Technology, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China., Luo J; Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environmental Science and Engineering, Hainan University, Haikou 570228, China. Electronic address: luojiwei@hainanu.edu.cn., Zeng H; Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China., Yang X; Key Laboratory of Agro-Forestry Environmental Processes and Ecological Regulation of Hainan Province, School of Environmental Science and Engineering, Hainan University, Haikou 570228, China., Hou X; Key Laboratory of Pollution Processes and Environmental Criteria of Ministry of Education and Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China., Lu X; Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, Tianjin International Joint Research Center for Environmental Biogeochemical Technology, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China. Electronic address: luxq@nankai.edu.cn.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2024 Sep 05; Vol. 476, pp. 135034. Date of Electronic Publication: 2024 Jun 29.
DOI: 10.1016/j.jhazmat.2024.135034
Abstrakt: Extracellular polymeric substances (EPS) secreted by organisms tend to encapsulate microplastics (MPs), forming an EPS-corona that affects the fate of MPs in marine ecosystems. However, the impact of the EPS-corona on the biotoxicity of MPs to marine organisms remains poorly understood. Herein, the effect of the EPS-corona on the toxicity of polystyrene (PS) MPs of different sizes (0.1 and 1 µm) to Skeletonema costatum (S. costatum) was investigated. The preferential adsorption of medium molecule weight (∼55 kDa) proteins onto PS MPs mainly contributed to the EPS-corona formation, decreasing the surface charge negativity of small-sized PS MPs (0.1 µm) by 72.4 %. Nitrogen (N) and oxygen (O) moieties in polysaccharides and proteins were identified as the preferential adsorption sites in the EPS-PS MPs interaction. Density functional theory (DFT) calculations confirmed the nuclear magnetic resonance spectroscopy (NMR) results, revealing that the binding mode between EPS and PS MPs was mainly hydrogen bonding. In addition, EPS-corona increased the cell density of S. costatum by 35.5-36.0 % when exposed to small-sized PS MPs (0.1 µm, 25-50 mg/L). These findings provide new insights into how EPS-corona affects the environmental fate and ecological risks associated with micro- and nano-sized plastics in marine ecosystems.
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