摘要
为评价纳米ZnO的生态安全性,研究了其对嗜热四膜虫(Tetrahymena thermophila)的水生生态毒性.显微成像表明,嗜热四膜虫食物泡是摄取纳米ZnO的主要部位.低ρ(纳米ZnO)对嗜热四膜虫的增殖具有促进作用(即"兴奋反应"),其中100mg/L时促进作用最明显,随着ρ(纳米ZnO)的进一步增加,其对嗜热四膜虫增殖的促进作用逐渐减弱.随着时间的延长,"兴奋反应"逐渐减弱.纳米ZnO能降低嗜热四膜虫的超氧化物歧化酶活性,且ρ(纳米ZnO)越高,抑制效应越强.纳米ZnO使嗜热四膜虫自由基清除能力下降,可能是其产生毒害作用的主要原因之一.
The aquatic ecotoxicity of nano-ZnO on Tetrahymena thermophila was investigated in order to evaluate its ecological safety. The research results with microscopic images showed that food vacuoles were the main place for Tetrahymena thermophila to distribute nano-ZnO after taking it in. The viability of Tetrahymena thermophila and its dose-effect relationship at various concentrations of nano-ZnO were also measured. Their results revealed that low mass concentrations of nano-ZnO exhibited dose-dependent growth stimulation to the ceils, while the stimulation effect of 100 mg/L nano-ZnO was the most striking. However, when the mass concentrations were higher than 100 mg/L, the effects of growth stimulation decreased. This stimulation effect gradually weakened with prolonged exposure time. The activity of superoxide dismutase （SOD） of Tetrahymena thermophila decreased with the increase of nano-ZnO concentration. Thus, the toxic effect of nano-ZnO on Tetrahymena thermophila is mainly due to the decrease of the ability to scavenge free radicals.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2009年第7期833-837,共5页
Research of Environmental Sciences
基金
国家质量监督检验检疫总局质检公益性行业科研专项(10-60)
