纳米TiO2对中肋骨条藻和杜氏盐藻的毒性效应研究

纳米材料的广泛应用增加了其进入海洋环境的风险，目前急需探明纳米材料的毒性效应和致毒机理。本文选用常见的纳米TiO₂ （nano-TiO₂）作为实验材料，通过进行微藻的生长抑制实验，测定微藻叶绿素的含量和脂质过氧化水平，探究了nano-TiO₂对两种海洋微藻中肋骨条藻（Skeletonema costatum）和杜氏盐藻（Dunaliella salina）的毒性效应。同时利用扫描电镜观测了微藻对nano-TiO₂的吸附作用，并初步研究了nano-TiO₂的沉降效应。结果表明，nano-TiO₂对海洋微藻S.costatum和D.salina的生长和光合作用均有抑制，且对两种微藻的毒性大小相似；nano-TiO₂会被微藻吸附，对微藻产生氧化损伤，抑制微藻的生长和光合作用，是nano-TiO₂对微藻产生毒性的主要原因；因nano-TiO₂在实验介质中会发生沉降，实际所有实验结果均在低于原设定浓度下获得。

Research on toxic effects of nano-TiO2 on Skeletonema costatum and Dunaliella salina

A large application of nano-materials increases their risk entering the marine environment.The primary purpose of this study is to explore the toxic effects and mechanisms of nano-TiO₂, which is widely applied in industry and commercial products.Algal growth inhibition test was carried out, and chlorophyll concentration and lipid peroxidation level were measured using Skeletonema costatum and Dunaliella salina as model organisms.Moreover, adsorption of nano-TiO₂ on microalgae was observed by SEM technique.The settlement of nano-TiO₂ particles in experimental medium with 24 h was also characterized.Results showed that both growth and photosynthesis of S.costatum and D.salina were inhibited by nano-TiO₂.Toxic effects of nano-TiO₂ on S.costatum were similar to those of D.salina.Adsorption of nano-TiO₂ and oxidative damages resulting from interactions between nano-TiO₂ and microalgae could inhibit growth and photosynthesis of microalgae, which were the main reasons for toxic effects of nano-TiO₂.The settlement of nano-TiO₂ particles in experiment medium caused the decrease of suspension concentration which had an influence on results.