多壁碳纳米管对铜绿微囊藻生长及生理特征的影响

碳纳米材料由于其具有优异的性能,得以广泛生产和使用,其不可避免会进入水环境中,对水生生态系统造成潜在影响。本文以铜绿微囊藻(Microcystis aeruginosa)为受试材料,通过暴露实验,研究了多壁碳纳米管(MWCNTs)单独作用对铜绿微囊藻的生物毒性和致毒机理。研究结果表明:低浓度(0.1 mg·L~(-1)和0.5 mg·L~(-1))的MWCNTs能刺激铜绿微囊藻的生长,超氧化物歧化酶(SOD)酶活增强;中低浓度(0.1～10.0 mg·L~(-1))范围内,MWCNTs促使光合色素合成,促进藻细胞增殖;高浓度(50mg·L~(-1)和100 mg·L~(-1)) MWCNTs对蓝藻生长产生抑制,严重抑制叶绿素a,藻细胞生命活力下降; MWCNTs浓度高于1 mg·L~(-1)时,SOD、过氧化物酶(POD)、过氧化氢酶(CAT)酶活性逐渐降低,丙二醛(MDA)的含量则逐步上升;可溶性蛋白含量与MWCNTs浓度有关,MWCNTs浓度低于5 mg·L~(-1)时,蛋白质含量增加,MWCNTs浓度高于5 mg·L~(-1)时,蛋白质含量逐渐减少。

Effects of Multi-walled Carbon Nanotubes on the Growth and Physiology of Microcystis aeruginosa

Due to the excellent characterisitics of carbon nanomaterials, they are widely produced and applied in many fields. Thus, they will inevitably enter water environment and cause potential impact on aquatic ecosystems. In the present study, the effects of multi-walled carbon nanotubes (MWCNTs) on Microcystis aeruginosa were investigated via exposure experiment. The results show that 0.1 mg·L-1 and 0.5 mg·L-1 MWCNTs can stimulate the growth of algae and enhance the activity of superoxide dismutase (SOD) and that 0.1-10.0 mg·L-1 MWCNTs can promote the synthesis of photosynthetic pigment and promote the proliferation of algae. However, 50 mg·L-1 and 100 mg·L-1 MWCNTs inhibit the growth of algae and seriously decrease the generation of chlorophyll a, leading to the decline of algae activity. When the concentration of MWCNTs is more than 0.1 mg·L-1, the activities of SOD, peroxidase (POD) and catalase (CAT) gradually decrease and MDA content gradually increases. The content of soluble protein depends on MWCNTs concentration. It increases when MWCNTs content is less than 5 mg·L-1 while it gradually decreases when MWCNTs content is more than 5 mg·L-1.