诺氟沙星对盐生杜氏藻、新月菱形藻和小球藻的生态毒性效应

基于室内培养实验，研究了海洋环境污染物诺氟沙星对盐生杜氏藻、新月菱形藻和小球藻的生态毒性效应。结果表明，实验浓度范围内，3种微藻生物量都随时间增加而增大，符合Logistic生长模型；诺氟沙星对3种微藻毒性效应差别较大，对新月菱形藻的毒性效应最低，EC₂₀（concentration for 20% of maximal effect）和EC₀₅（concentration for 5% of maximal effect）分别为25.36 mg/L和1.76 mg/L；对盐生杜氏藻的毒性效应较低，EC₂₀和EC₀₅分别为10.54 mg/L和1.25 mg/L；对小球藻的毒性效应最高，EC₂₀和EC₀₅分别为5.33 mg/L和0.01 mg/L；诺氟沙星对三种海洋微藻的抑制率增幅均随浓度增加趋缓。另外，在1 mg/L的浓度下，新月菱形藻的B_f值略高于对照组，这可能与毒性兴奋效应有关；小球藻的指数增长期随着诺氟沙星浓度的增大有着明显缩短的趋势。基于物种敏感性分布，得到诺氟沙星污染物对海洋生态系统的预测非效应浓度（predicted no effect concentration，PNEC）为0.096 mg/L。

Effects of norfloxacin on Dunaliella salina, Nitzschia closterium f. minutissima and Chlorella vulgaris

Based on laboratory cultivate experiments, this project studied the ecological toxic effects of norfloxacin, a marine environmental pollutant, on Dunaliella salina, Nitzschia closterium f.minutissima and Chlorella vulgaris.The results showed that, within the experimental concentration range, with the increase of the time, the biomass of the three microalgae increased, which conforms with the Logistic growth model.The toxicity effect of norfloxacin on the three kinds of microalgae was different, and this effect was the lowest in the Nitzschia closterium f.minutissima, the EC₂₀ and the EC₀₅ are 25.36 mg/L and 1.76 mg/L; the toxicity of Dunaliella salina is low, the EC₂₀ and the EC₀₅ are 10.54 mg/L and 1.25 mg/L; the toxicity effect of Chlorella vulgaris is the highest, the EC₂₀ and the EC₀₅ are 5.33 mg/L and 0.01 mg/L.With the increase of concentration, the increase in the inhibitory rate of norfloxacin to three kinds of marine microalgae decreased.In addition, at 1 mg/L, the B_f of Nitzschia closterium f.minutissima was slightly higher than that of the control group, which may be related to the toxic excitatory effect.With the increase of norfloxacin concentration, the exponential growth period of Chlorella vulgaris was significantly shortened.Based on the species sensitivity distribution, the predicted no effect concentration (PNEC) of the norfloxacin contaminant to marine ecosystem was 0.096 mg/L.