Toxicological effects of nanometer titanium dioxide (nano-TiO2) on Chlamydomonas reinhardtii
Toxicological effects of nanometer titanium dioxide (nano-TiO2) on Chlamydomonas reinhardtii
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纳米二氧化钛（nano-TiO2）对莱茵衣藻的毒理学效应
DOI：
10.1016/j.ecoenv.2012.07.019
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发表时间：
2012-10-01
影响因子：
6.8
通讯作者：
Wang, Gaohong
中科院分区：
文献类型：
--
作者：
Chen, Lanzhou;Zhou, Lina;Wang, Gaohong
研究了纳米二氧化钛（nano-TiO 2）对单细胞绿色莱茵衣藻（Chlamydiumreinhardtii）的毒性作用，并对其生理和细胞超微结构进行了观察。结果表明，纳米TiO 2抑制了藻的光合效率和细胞生长，但藻体内叶绿素a含量没有变化，而类胡萝卜素和叶绿素B含量增加。丙二醛（MDA）含量在染毒8 h后达到最大值，72 h后降至中等水平。电子显微镜图像表明，随着纳米TiO 2浓度的增加，大量的C. reinhardtii细胞受到损伤：叶绿体数量下降，各种其他细胞器降解，发生质体降解，发现TiO 2纳米颗粒位于细胞壁和细胞膜内。还注意到，细胞表面被TiO 2颗粒包围，这可能阻碍细胞与其周围环境之间的物质交换。综上所述，纳米TiO 2对C. reinhardtii的反应包括细胞表面聚集、光合作用抑制、膜脂过氧化和新蛋白质合成; reinhardtii对纳米TiO 2的反应是一个快速的过程，发生在暴露后24 h内，可能与生理应激系统有关，以减轻伤害。皇冠版权所有（C）2012由Elsevier Inc.发布。All rights reserved.
The toxicological effects of nanometer titanium dioxide (nano-TiO2) on a unicellular green alga Chlamydomonas reinhardtii were assessed by investigating the changes of the physiology and cyto-ultrastructure of this species under treatment. We found that nano-TiO2 inhibited photosynthetic efficiency and cell growth, but the content of chlorophyll a content in algae did not change, while carotenoid and chlorophyll b contents increased. Malondialdehyde (MDA) content reached maximum values after 8 h exposure and then decreased to a moderately low level at 72 h. Electron microscopy images indicated that as concentrations of nano-TiO2 increased, a large number of C. reinhardtii cells were noted to be damaged: the number of chloroplasts declined, various other organelles were degraded, plasmolysis occurred, and TiO2 nanoparticles were found to be located inside cell wall and membrane. It was also noted that cell surface was surrounded by TiO2 particles, which could present an obstacle to the exchange of substances between the cell and its surrounding environment. To sum up, the effect of nano-TiO2 on C. reinhardtii included cell surface aggregation, photosynthesis inhibition, lipid peroxidation and new protein synthesis, while the response of C. reinhardtii to nano-TiO2 was a rapid process which occurs during 24 h after exposing and may relate to physiological stress system to mitigate damage. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.