Liu Zeliang, Cao Xuanlin, Wu Manli, Huang Wenjie, Dong Xia, Chen Xing, Zhang Chun
Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Key Laboratory of Northwest Water Resource, Environment and Ecology, MOE, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China; Shaanxi province Higher Education Key Laboratory for Soil Pollution Remediation and Solid Waste Resource Utilization, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China.
Shaanxi province Higher Education Key Laboratory for Soil Pollution Remediation and Solid Waste Resource Utilization, Xi'an University of Architecture and Technology, Xi'an, 710055, People's Republic of China.
Environ Res. 2025 May 15;273:121228. doi: 10.1016/j.envres.2025.121228. Epub 2025 Feb 25.
Perfluorobutanoic acid (PFBA), an emerging alternative to perfluorooctanoic acid (PFOA), has become increasingly prevalent in aquatic ecosystems, yet its ecotoxicological impacts remain poorly understood. This study investigated the aquatic toxicity of PFBA using the freshwater algae Chlorella vulgaris (C. vulgaris) as a model organism, employing a 96h pre-exposure assay to determine the median effective concentration followed by acute toxicity experiments analyzing multiple endpoints including growth, photosynthetic parameters, oxidative stress markers, and antioxidant enzyme activities. Computer simulation techniques were utilized to illustrate the underlying molecular mechanisms of PFBA toxicity. The results showed that the 96h-EC value of PFBA was 154.88 mg/L, which is comparable to conventional per- and polyfluoroalkyl substances (PFAS). Acute toxicity experiments revealed a biphasic dose-response relationship to the algal growth with the hormetic effects at the lower concentrations (30.97-92.93 mg/L) but inhibition at the higher levels (123.91-185.86 mg/L) of PFBA. High dosages of PFBA significantly decreased the maximum photosynthetic yield (Fv/Fm) and relative electron transfer rate (rETR), while inducing oxidative stress and inhibiting superoxide dismutase (SOD) and catalase (CAT) activities. Future AlphaFold2 modeling and molecular docking simulations demonstrated the potential binding of PFBA to photosystem II D1 C-terminal processing protease (PSII D1 protein), SOD, and CAT. These findings reveal a complex toxicity mechanism of PFBA on C. vulgaris involving photosynthetic disruption, oxidative stress, and antioxidant system impairment, contributing to the understanding of short-chain PFAS alternative ecotoxicity in aquatic ecosystems.
全氟丁酸（PFBA）作为全氟辛酸（PFOA）的一种新兴替代品，在水生生态系统中越来越普遍，但其生态毒理学影响仍知之甚少。本研究以淡水藻类普通小球藻（C. vulgaris）为模式生物，研究了PFBA的水生毒性，采用96小时预暴露试验确定半数有效浓度，随后进行急性毒性实验，分析多个终点指标，包括生长、光合参数、氧化应激标志物和抗氧化酶活性。利用计算机模拟技术阐明PFBA毒性的潜在分子机制。结果表明，PFBA的96小时EC值为154.88mg/L，与传统的全氟和多氟烷基物质（PFAS）相当。急性毒性实验表明，PFBA对藻类生长呈现双相剂量反应关系，低浓度（30.97 - 92.93mg/L）时有刺激效应，而高浓度（123.91 - 185.86mg/L）时则有抑制作用。高剂量的PFBA显著降低了最大光合产量（Fv/Fm）和相对电子传递速率（rETR），同时诱导氧化应激并抑制超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。未来的AlphaFold2建模和分子对接模拟表明，PFBA可能与光系统II D1 C末端加工蛋白酶（PSII D1蛋白）、SOD和CAT结合。这些发现揭示了PFBA对普通小球藻的复杂毒性机制，包括光合破坏、氧化应激和抗氧化系统损伤，有助于理解水生生态系统中短链PFAS替代品的生态毒性。
