National and Local Joint Engineering Research Center of Biomedical Functional Materials, Jiangsu Collaborative Innovation Center of Biomedical Functional Materials, School of Chemistry and Materials Science, School of Life Sciences, Nanjing Normal University, Nanjing, 210023, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China.
Environ Pollut. 2022 Jan 1;292(Pt A):118308. doi: 10.1016/j.envpol.2021.118308. Epub 2021 Oct 6.
Aggravating the pollution of microcystins (MCs) in freshwater environments is detrimental to aquatic living organisms and humans, and thus threatens the stability of ecosystems. Some environmental factors have been verified to promote the production of MCs in Microcystis aeruginosa, thereby aggravating the pollution of MCs. However, the effects of cerium (Ce), the most abundant rare earth element in global water environments, on the production of MCs in M. aeruginosa are unknown. Here, Lake Taihu water was selected as a representative of freshwater environments. By using interdisciplinary methods, it was found that: (1) the exposure level of Ce [Ce(III) and Ce(IV)] in Lake Taihu water is in the range of 0.271-0.282 μg/L; (2) Ce exposure in Lake Taihu water promoted the contents of three main MCs (MC-LR, MC-LW and MC-YR) in M. aeruginosa and water; (3) a cellular mechanism of Ce promoting the production of MCs in M. aeruginosa in Lake Taihu water was suggested: Ce enhanced endocytosis in cells of M. aeruginosa to promote the essential element uptake by M. aeruginosa for MC synthesis. Thus, Ce exposure in Lake Taihu water aggravates the pollution of MCs via enhancing endocytosis in cells of M. aeruginosa. The results provide reference for assessing the environmental risk of Ce in water environments, investigating the mechanism of the pollution of MCs induced by environmental factors, and developing strategies aimed at preventing and controlling the pollution of MCs.
加剧淡水环境中微囊藻毒素（MCs）的污染对水生生物和人类有害，从而威胁生态系统的稳定性。一些环境因素已被证实可促进铜绿微囊藻中 MCs 的产生，从而加剧 MCs 的污染。然而，铈（Ce）作为全球水环境中最丰富的稀土元素，对铜绿微囊藻中 MCs 产生的影响尚不清楚。本研究选择太湖水作为淡水环境的代表，采用多学科方法发现：（1）太湖水暴露的 Ce[Ce(III)和 Ce(IV)]水平在 0.271-0.282μg/L 范围内；（2）太湖水 Ce 暴露促进了铜绿微囊藻和水中三种主要 MCs（MC-LR、MC-LW 和 MC-YR）的含量；（3）提出了太湖水 Ce 促进铜绿微囊藻中 MCs 产生的细胞机制：Ce 增强铜绿微囊藻细胞的内吞作用，以促进铜绿微囊藻合成 MC 所需的必需元素的摄取。因此，太湖水 Ce 暴露通过增强铜绿微囊藻细胞的内吞作用加剧了 MCs 的污染。研究结果为评估水环境中 Ce 的环境风险、研究环境因素诱导的 MCs 污染机制以及制定防控 MCs 污染的策略提供了参考。
