全氟辛酸对大肠杆菌的氧化胁迫和膜损伤

发布时间：2018-07-23 11:54

【摘要】：全氟辛酸(perfluorooctanoic acid,PFOA)因其具有极高的化学稳定性和良好的疏水疏油性而在工业生产中广泛使用,但近年来被认为是一种在环境中广泛分布的持久性有机污染物.利用流式细胞术等检测技术,研究了PFOA对大肠杆菌(Escherichia coli,E.coli)的氧化胁迫和膜损伤,并对其毒性作用机制进行了初步的探索.结果表明,在PFOA胁迫下,大肠杆菌胞内活性氧(reactive oxygen species,ROS)含量增加,膜脂肪酸不饱和度降低,丙二醛(malondialdehyde,MDA)浓度升高、细胞膜通透性增大、跨膜电位降低,而细胞膜上的Na+K+-ATPase、Ca2+Mg2+-ATPase活性随时间的延长代偿性地先上升后降低.由此说明,在PFOA胁迫下,大肠杆菌细胞内升高的ROS与细胞膜不饱和脂肪酸发生过氧化反应,降低膜脂肪酸的饱和度,使得MDA在细胞内积累,进一步引起细胞膜损伤及其上相关ATPase活性降低,最终导致大肠杆菌细胞失活或死亡.实验结果对研究PFOA胁迫下环境生态毒理提供更多依据.
[Abstract]:Perfluorooctanoic acid (perfluorooctanoic) is widely used in industrial production because of its high chemical stability and good hydrophobicity. The oxidative stress and membrane damage of Escherichia coli (Escherichia coli) caused by PFOA were studied by flow cytometry, and the mechanism of its toxicity was explored. The results showed that under PFOA stress, the content of reactive oxygen species (reactive oxygen) in E. coli increased, the fatty acid unsaturation decreased, the concentration of malondialdehyde (malondialdehyde) increased, the membrane permeability increased, and the transmembrane potential decreased. On the other hand, the activity of Ca 2 Mg2-ATPase on the membrane of Na K-AT Paseate increased at first and then decreased with the prolongation of time. Therefore, under PFOA stress, the increased Ros in E. coli cells reacted with the unsaturated fatty acids of the cell membrane, which decreased the saturation of the fatty acids in the membrane and resulted in the accumulation of MDA in the cells. Furthermore, it caused cell membrane damage and the decrease of ATPase activity, which resulted in inactivation or death of Escherichia coli cells. The results provide more evidence for the study of environmental ecotoxicology under PFOA stress.
【作者单位】：暨南大学环境学院;广东省环境污染与健康重点实验室;广东省环境污染控制与修复材料工程技术研究中心;广州市环境暴露与健康重点实验室;
【基金】：国家自然科学基金委-广东省联合基金重点项目(U1501233) 国家自然科学基金项目(21377047,21577049) 广东省科技计划项目(2009B030802008)
【分类号】：X171.5

【相似文献】