School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China; State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, 73 East Beijing Road, Nanjing, 210008, China; Key Laboratory of Virtual Geographic Environment (Nanjing Normal University), Ministry of Education, Nanjing, 210023, China.
School of Geography, School of Environment, Nanjing Normal University, Nanjing, 210023, China.
Toxicon. 2022 Apr 30;210:49-57. doi: 10.1016/j.toxicon.2022.02.020. Epub 2022 Feb 22.
With the continued influx and accumulation of polycyclic aromatic hydrocarbons (PAHs) in eutrophic waters, the effects of PAHs on cyanobacteria bloom need to be clarified. PAHs usually existed as mixtures in aquatic environments, but the combined toxicity of PAH mixtures to toxigenic cyanobacteria remained unknown. This study investigated the effects of phenanthrene (Phe) and benzo [a]pyrene (BaP), alone or in combination, on the growth and physiology of Microcystis aeruginosa. The results showed that a hormesis effect on growth at low doses of the single Phe (≤1 mg/L) or PAH mixtures (≤0.279 mg/L) was observed, whereas the single BaP induced significant growth inhibitions at all concentrations (≥0.2 mg/L). The median effective concentrations (96 h) for Phe, BaP and their mixtures were 4.29, 1.29 and 1.07 mg/L, respectively. Mixture toxicity models showed that Phe and BaP elicited a synergistic interaction on M. aeruginosa. The synergy may be ascribed to the excessive oxidative stress induced by PAH mixtures, which further led to membrane structure damages, photosynthesis inhibitions and decreased metabolic activity. Moreover, the microcystins (MCs) release significantly increased by 25.3% and 31.9% upon exposure to 0.558 and 1.116 mg/L of PAH mixtures. In all, this study suggested that the enhanced release of MCs by PAH mixtures might exacerbate potential risks to the aquatic environment.
随着多环芳烃（PAHs）在富营养化水中的持续涌入和积累，PAHs 对蓝藻水华的影响需要得到澄清。PAHs 通常在水生环境中以混合物的形式存在，但 PAH 混合物对产毒蓝藻的联合毒性仍不清楚。本研究调查了单独或联合使用菲（Phe）和苯并[a]芘（BaP）对铜绿微囊藻生长和生理的影响。结果表明，在低剂量的单一 Phe（≤1mg/L）或 PAH 混合物（≤0.279mg/L）下观察到生长的兴奋效应，而单一 BaP 在所有浓度（≥0.2mg/L）下均诱导显著的生长抑制。Phe、BaP 及其混合物的 96 小时半数有效浓度（EC50）分别为 4.29、1.29 和 1.07mg/L。混合物毒性模型表明，Phe 和 BaP 对铜绿微囊藻表现出协同相互作用。协同作用可能归因于 PAH 混合物引起的过度氧化应激，这进一步导致膜结构损伤、光合作用抑制和代谢活性降低。此外，暴露于 0.558 和 1.116mg/L 的 PAH 混合物后，微囊藻毒素（MCs）的释放分别显著增加了 25.3%和 31.9%。总之，本研究表明，PAH 混合物增强 MCs 的释放可能会加剧对水生环境的潜在风险。
