摘要
近年来,纳米银(AgNPs)的广泛应用导致其不可避免地被释放到周围环境中,并通过地表径流最终汇集到近岸海域。为探究纳米银污染对海洋微藻的毒性效应,以杜氏盐藻为受试对象,设置不同质量浓度的纳米银处理组(0、10、25、50、100 mg·L^(-1))进行短期6 d暴露试验。通过分析杜氏盐藻藻细胞密度、光合色素含量、叶绿素荧光参数、抗氧化系统以及超微结构等指标,揭示杜氏盐藻对纳米银的生理生化响应。结果显示,质量浓度为100 mg·L^(-1)组纳米银对杜氏盐藻的藻细胞密度、光合色素含量、叶绿素荧光参数、抗氧化系统和超微结构等指标产生显著影响(P<0.05)。杜氏盐藻在不同浓度纳米银暴露6 d后藻细胞密度显著降低(P<0.05)。100 mg·L^(-1)组与对照组相比,藻细胞密度下降了48%。试验第4天,与对照组相比,50 mg·L^(-1)组和100 mg·L^(-1)组藻细胞叶绿素a和叶绿素b含量均显著下降(P<0.05),但试验第6天,各试验组叶绿素a、叶绿素b和类胡萝卜素含量与对照组均无显著差异(P>0.05)。试验第6天杜氏盐藻最大电子传递速率(ETRmax)随AgNPs浓度增加而下降,25 mg·L^(-1)组的超氧化物歧化酶、过氧化氢酶活性和丙二醛含量均显著高于对照组(P<0.05),同时100 mg·L^(-1)组的丙二醛含量显著升高,蛋白含量却显著低于对照组(P<0.05)。超微结构显示,高浓度(100 mg·L^(-1))纳米银导致杜氏盐藻细胞膜完整性遭到破坏,但藻细胞并未出现明显死亡现象。该研究表明纳米银短期暴露对杜氏盐藻的生长、光合作用以及超微结构产生消极影响,导致杜氏盐藻叶绿素含量下降,细胞膜通透性发生改变,并引发脂质过氧化,进而破坏光合作用和呼吸作用等。杜氏盐藻通过提高抗氧化酶活性来面对氧化应激损伤达到自我保护作用。该研究为评估AgNPs在水生环境中的生态风险提供了重要科学依据,提示在AgNPs的应用和排放管理中需充分考虑其对水生生态系统的潜在危害。
In recent years,the wide application of AgNPs has led to its inevitable release into the surrounding environment and eventually to the coastal waters through surface runoff.To explore the toxic effects of AgNPs pollution on marine microalgae,Dunaliella salina was used as the test object,and different concentrations of AgNPs treatment groups(0,10,25,50,100 mg·L^(-1))were set for a short-term 6-day exposure test.By analyzing the cell density,photosynthetic pigment content,chlorophyll fluorescence parameters,antioxidant system and ultrastructure of Dunaliella salina,it was found that AgNPs affected Dunaliella salina and its physiological and biochemical responses.The results showed that when the mass concentration was 100 mg·L^(-1),silver nanoparticles had a significant effect on the algal cell density,photosynthetic pigment content,chlorophyll fluorescence parameters,antioxidant system and ultrastructure of Dunaliella salina(P<0.05).The cell density of Dunaliella salina decreased significantly after 6 days of exposure to different concentrations of AgNPs(P<0.05).Compared with the control group,the cell density in the 100 mg·L^(-1)group decreased by 48%.On the 4th day of the experiment,compared with the control group,the contents of chlorophyll a and chlorophyll b in algal cells of 50 mg·L^(-1)group and 100 mg·L^(-1)group decreased significantly(P<0.05),but on the 6th day of the experiment,the contents of chlorophyll a,chlorophyll b and carotenoids in each experimental group were not significantly different from those in the control group(P>0.05).The maximum electron transport rate(ETRmax)of Dunaliella salina decreased with the increase of AgNPs concentration on the 6th day of the experiment.The activities of superoxide dismutase and catalase,as well as the malondialdehyde(MDA)content,in the 25 mg·L^(-1)group were significantly higher than those in the control group(P<0.05).At the same time,the malondialdehyde content in the 100 mg·L^(-1)group increased significantly(P<0.05),while the protein content was significantly lower than that in the control group(P<0.05).Ultrastructural analysis showed that AgNPs at a high concentration(100 mg·L^(-1))caused damage to the cell membrane integrity of Dunaliella salina,but the algal cells did not show obvious death.This study shows that short-term exposure to AgNPs has a negative impact on the growth,photosynthesis and ultrastructure of Dunaliella salina,resulting in a decrease in chlorophyll content of Dunaliella salina,changes in cell membrane permeability,and lipid peroxidation,which in turn disrupts photosynthesis and respiration.Dunaliella salina achieves self-protection against oxidative stress damage by increasing the activity of antioxidant enzymes.This study provides an important scientific basis for assessing the ecological risks of AgNPs in the aquatic environment,suggesting that the potential hazards of AgNPs to aquatic ecosystems should be fully considered in the application and emission management of AgNPs.
作者
张春雨
邵蓬
唐磊
孟志
周子纯
李文婧
郭帅良
周文礼
窦勇
张丹
ZHANG Chunyu;SHAO Peng;TANG Lei;MENG Zhi;ZHOU Zichun;LI Wenjing;GUO Shuailiang;ZHOU Wenli;DOU Yong;ZHANG Dan(Key Laboratory of Aqua-ecology and Aquaculture of Tianjin,College of Fisheries Sciences,Tianjin Agricultural University,Tianjin 300384,China)
出处
《生态毒理学报》
北大核心
2026年第1期530-539,共10页
Asian Journal of Ecotoxicology
基金
国家自然科学基金资助项目(32303038)
天津市渔业绿色发展项目(YYLSFZ202501)。
关键词
纳米银
杜氏盐藻
急性毒性
生态风险
AgNPs
Dunaliella salina
acute toxicity
ecological risk
