Effect of TiO2 nanoparticles and multiwall carbon nanotubes on the freshwater diatom Nitzschia frustulum: evaluation of growth,cellular components and morphology |
| |
Authors: | Kun Jia Chenglong Sun Yulin Wang Xin Li Weijie Mu |
| |
Affiliation: | College of Life Science and Technology, Harbin Normal University, Harbin, People’s Republic of China |
| |
Abstract: | Great attention should be paid to the possible impacts of various nanoparticles on aquatic organism. Freshwater diatoms are essential components of phytoplankton and play a critical role in bioassessment of nanoparticle exposure in the environment. In this study, cell growth was inhibited by TiO2-NPs and MWCNTs, the 24?h EC50 values of TiO2-NPs and MWCNTs to Nitzschia frustulum were 20.75 and 24.64?mg?L?1, respectively. Significant decreases of Chl a content after TiO2-NPs exposures were detected and the Chl a content of N. frustulum was obviously increased by MWCNTs treatment at lower concentration. The ROS was detected in N. frustulum after TiO2-NPs and MWCNTs exposures. The MDA content was significantly induced by TiO2-NPs at lower concentrations of 24 and 48?h exposure; meanwhile, it increased at all tested concentrations at 24?h MWCNTs exposure. The SOD enzyme was induced by 72 and 96?h TiO2-NPs exposure, and increased by MWCNTs treatment at 96?h in N. frustulum. Scanning electron microscopy results revealed that N. frustulum had obvious cell deformation after TiO2-NPs treatment. The result showed that the physiological and biochemical response mechanisms after NPs exposure of diatom were species-specific, and in relation to the exposure concentration and time. |
| |
Keywords: | Nitzschia frustulum titanium dioxide nanoparticles multi-walled carbon nanotubes biochemical responses morphological changes |
|
|