Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production
Toxicity of nano-TiO2 on algae and the site of reactive oxygen species production
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纳米TiO2对藻类的毒性及活性氧产生部位
DOI：
10.1016/j.aquatox.2014.10.014
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发表时间：
2015-01-01
影响因子：
4.5
通讯作者：
Wang, Zhenyu
中科院分区：
文献类型：
--
作者：
Li, Fengmin;Liang, Zhi;Wang, Zhenyu
鉴于纳米材料的广泛使用，它们可能会进入水生环境并损害藻类的生长，而藻类是水生生态系统的主要生产者。因此，水生生态系统的平衡可能被破坏。在这项研究中，Karenia brevis和中肋骨条藻暴露于纳米TiO 2（纳米TiO 2，平均粒径为5-10 nm，比表面积为210 +/- 10 m（2）g（-1）），以评估纳米TiO 2对藻类的影响。透射电子显微镜-能量色散X射线能谱（TEM-EDX）和扫描电子显微镜（SEM）的结果表明，纳米TiO 2在藻悬浮液中的聚集。纳米二氧化钛也被发现在藻类细胞内。纳米TiO 2对两种藻类的生长均有抑制作用。纳米TiO 2对K. brevis和S.中肋骨条藻的最低生物量分别为10.69和7.37 mg L-1。透射电镜观察表明，K. nano-TiO_2处理后，brevis细胞被破坏，细胞器几乎不清晰。丙二醛（MDA）含量显著高于对照组（P < 0. 05）。brevis和S.与对照组相比，中肋骨显著增加（p < 0.05）。同时，K. brevis和S.肋骨以不同的方式改变。两种动物体内活性氧（ROS）水平均显著高于对照组（p < 0.05）。K. brevis和S.通过添加不同电子转移链的抑制剂，研究了纳米TiO 2对中肋骨的影响。实验结果表明，纳米TiO 2对K. brevis和S.肋骨这种效应归因于藻细胞内ROS产生引起的氧化应激。抗氧化酶的水平发生变化，破坏了氧化与抗氧化之间的平衡。因此，藻类被ROS的积累所伤害，导致脂质氧化并抑制藻类生长。电子传递链抑制剂的研究表明，K.短细胞是叶绿体。(C)2014爱思唯尔有限公司版权所有。
Given the extensive use of nanomaterials, they may enter aquatic environments and harm the growth of algae, which are primary producers in an aquatic ecosystem. Thus, the balance of an aquatic ecosystem may be destroyed. In this study, Karenia brevis and Skeletonema costatum were exposed to nano-TiO2 (anatase, average particle size of 5-10 nm, specific surface area of 210 +/- 10 m(2) g(-1)) to assess the effects of nano-TiO2 on algae. The findings of transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDX) and scanning electron microscopy (SEM) demonstrate aggregation of nano-TiO2 in the algal suspension. Nano-TiO2 was also found to be inside algal cells. The growth of the two species of algae was inhibited under nano-TiO2 exposure. The 72 h EC50 values of nano-TiO2 to K. brevis and S. costatum were 10.69 and 7.37 mg L-1, respectively. TEM showed that the cell membrane of K. brevis was destroyed and its organelles were almost undistinguished under nano-TiO2 exposure. The malondialdehyde (MDA) contents of K. brevis and S. costatum significantly increased compared with those of the control (p < 0.05). Meanwhile, superoxide dismutase (SOD) and catalase activities (CAT) of K. brevis and S. costatum changed in different ways. The reactive oxygen species (ROS) levels in both species were significantly higher than those of the control (p < 0.05). The site of ROS production and accumulation in K. brevis and S. costatum under nano-TiO2 exposure was explored with the addition of inhibitors of different electron transfer chains. This study indicated that nano-TiO2 in algal suspensions inhibited the growth of K. brevis and S. costatum. This effect was attributed to oxidative stress caused by ROS production inside algal cells. The levels of anti-oxidative enzymes changed, which destroyed the balance between oxidation and anti-oxidation. Thus, algae were damaged by ROS accumulation, resulting in lipid oxidation and inhibited algae growth. The inhibitors of the electron transfer chain showed that the site of ROS production and accumulation in K. brevis cells was the chloroplast. (C) 2014 Elsevier B.V. All rights reserved.