Zhang Kai, Wei Ziqin, Wang Yixuan, Shui Weikai, Jia Bingchan, Huang Zhuo, Feng Qian
Nanjing Jiangning District Water Affairs Bureau, Nanjing, China.
Nanjing No. 1 Middle School, Nanjing, China.
PeerJ. 2025 Jun 11;13:e19553. doi: 10.7717/peerj.19553. eCollection 2025.
In aquatic ecosystems, microalgae experience the adverse effects of the widely used disinfectant component, polyhexamethylene guanidine (PHMG). Our research focused on the model alga, , examining how PHMG exposure influences its growth, photosynthesis, metabolic byproducts, and antioxidant defenses. We observed a range of effects from slight disturbances at low PHMG concentrations to significant growth inhibition at higher levels, suggesting a hormesis-like response. Specifically, PHMG exposure led to reduced chlorophyll content, impaired Photosystem II efficiency, and decreased photosynthetic activity. Interestingly, the algae responded to stress by increasing antioxidant enzyme activities and stress biomarkers. Structural equation modeling (SEM) revealed that PHMG primarily disrupts the photosynthetic apparatus, which in turn affects metabolic and antioxidant responses, culminating in reduced algal biomass. Our results contribute to the understanding of the threats posed to aquatic life by the ubiquitous and ever-increasing pollution from chemical disinfectants, and highlight the urgency of mitigation measures.
在水生生态系统中，微藻会受到广泛使用的消毒剂成分聚六亚甲基胍（PHMG）的不利影响。我们的研究聚焦于模式藻类，研究了暴露于PHMG如何影响其生长、光合作用、代谢副产物和抗氧化防御。我们观察到一系列影响，从低浓度PHMG时的轻微干扰到较高浓度时的显著生长抑制，这表明存在类似毒物兴奋效应的反应。具体而言，暴露于PHMG会导致叶绿素含量降低、光系统II效率受损以及光合活性下降。有趣的是，藻类通过增加抗氧化酶活性和应激生物标志物来应对压力。结构方程模型（SEM）表明，PHMG主要破坏光合机构，进而影响代谢和抗氧化反应，最终导致藻类生物量减少。我们的研究结果有助于理解化学消毒剂无处不在且不断增加的污染对水生生物构成的威胁，并凸显了缓解措施的紧迫性。
