纳米氧化铁对聚球藻的毒性效应及富里酸的调节作用

发布时间：2018-04-10 18:26

本文选题：nFe_2O_3 + 聚球藻　；参考：《南京农业大学》2015年硕士论文

【摘要】：纳米材料由于其特殊的性质,得到越来越广泛的应用,不可避免的进入环境中对生物造成毒性效应。近年来以藻类为对象的纳米毒性研究日益增加,但是绝大部分研究集中于真核生物并且忽略了复杂水环境中天然有机物的影响。本文采用原核生物聚球藻为研究对象,系统地探讨纳米氧化铁(nFe2O3)对聚球藻48h急性毒性以及15d慢性毒性的生物学效应,解析添加天然有机物富里酸对纳米颗粒的物理化学性质和毒性效应的影响。1)48h急性实验显示nFe2O3对聚球藻细胞有毒性效应,且毒性程度大小与纳米颗粒浓度呈现正相关,在低浓度下,纳米颗粒无明显毒性影响,当nFe2O3浓度大于10mg·L-1时,细胞内叶绿素、可溶性总蛋白以及总糖含量都显著性降低。实验结果说明当nFe2O3浓度大于10mg·L-1时,会使聚球藻细胞光合作用受阻、生理代谢紊乱。2)高浓度nFe2O3暴露能使聚球藻产生显著的氧化应激现象,如当浓度为30 mg·L-1时,CAT活力是对照的4.44倍,POD活力是对照的3.31倍,SOD活力是对照的3.34倍。结果显示nFe2O3可能会使藻细胞产生过量的ROS,抗氧化酶是机体抵御外界环境胁迫的第一道防御系统。3)一定浓度范围内天然有机物富里酸(FA)能减缓nFe2O3对聚球藻的毒性效应,10mg·L-1nFe2O3在10、20和40mg·L-1FA的共同作用下,细胞内叶绿素、可溶性总蛋白、总糖含量以及抗氧化酶水平(CAT、POD和SOD活力)都与对照无显著差别。4)本实验将纳米颗粒对藻细胞的急性毒性和慢性毒性进行比较,nFe2O3对聚球藻15d的慢性毒性研究表明,nFe2O3颗粒对聚球藻细胞无明显生长胁迫和毒性效应,细胞内生理代谢都基本恢复到对照水平。
[Abstract]:Nanomaterials are more and more widely used because of their special properties.In recent years, the research on the nano-toxicity of algae is increasing, but most of the studies focus on eukaryotes and ignore the influence of natural organic matter in complex water environment.In this paper, the biological effects of nano-ferric oxide nFe2O3) on the acute toxicity of Chlorella spp. for 48 h and the chronic toxicity at 15 d were studied.The effects of natural organic compound fulvic acid on the physical and chemical properties and toxicity of nanoparticles were analyzed. The acute experiment for 48 h showed that nFe2O3 had a toxic effect on Chlorella polycystis cells, and the degree of toxicity was positively correlated with the concentration of nanoparticles.When the concentration of nFe2O3 was higher than 10mg L-1, the contents of chlorophyll, soluble total protein and total sugar were significantly decreased.The results showed that when the concentration of nFe2O3 was higher than 10mg L-1, the photosynthesis of chlorella cells was blocked, and the physiological metabolic disorder. 2) the exposure of high concentration of nFe2O3 to Chlorella spp resulted in significant oxidative stress.When the concentration was 30 mg L ~ (-1), the activity of cat was 4.44 times of that of the control, and the activity of POD was 3.31 times of that of the control, and the activity of SOD was 3.34 times of that of the control.The results showed that nFe2O3 might make algal cells produce excessive ROS.Antioxidant enzyme is the first defense system to resist external environmental stress. 3) the natural organic substance, fulvic acid FAA, in a certain concentration range, can slow down the toxicity of nFe2O3 to Chlorella spp.10mg L-1nFe2O3 was combined with 40mg L-1FA.Intracellular chlorophyll, soluble total protein,There was no significant difference in total sugar content and antioxidant enzyme level. (4) in this experiment, the acute and chronic toxicity of nanoparticles to algal cells was compared. The chronic toxicity of nFe2O3 to Chlorella aggregates for 15 days was studied.There was no obvious growth stress and toxic effect of granules on chlorella cells.The intracellular physiological metabolism was basically restored to the control level.
【学位授予单位】：南京农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X171.5;TB383.1

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