邻苯二甲酸二丁酯（DBP）对斜生栅藻的致毒效应研究

为了评估邻苯二甲酸二丁酯(DBP)对水生生物的毒性效应,采用室内培养的方法,研究了DBP对斜生栅藻(Scenedesmus obliquus)的急性毒性效应.实验设置5个暴露组(5、10、20、50、100mg·L-1)和1个对照组(0mg·L-1),暴露96h后分别测定DBP对斜生栅藻生长量、光合色素含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量等生理生化指标的影响.结果表明,各暴露组DBP对斜生栅藻的生长均有抑制作用,随DBP暴露浓度的增大,藻细胞密度逐渐降低,显示出明显的剂量-效应关系.DBP对斜生栅藻的24、48、72、96h的EC50值分别为3.31、15.49、1.95、2.21mg·L-1.叶绿素a、b及类胡萝卜素含量随着DBP暴露浓度的增大呈现相同的变化趋势,均为低浓度(5～10mg·L-1)上升,高浓度(10～100mg·L-1)下降.随DBP暴露浓度的增大,斜生栅藻SOD活性表现为先激活后抑制,在20mg·L-1时SOD活性达到最大值(与对照比较,p<0.05);当DBP暴露浓度≥10mg·L-1时,MDA含量随DBP浓度的增大显著增加(与对照比较,p<0.05,p<0.01).

Toxic Effects of Dibutyl Phthalate(DBP)on Scenedesmus obliquus

In order to study the toxic effects of DBP on the fresh algae,Scenedesmus obliquus was exposed to DBP of five concentrations(5,10,20,50,100mg·L-1)and a control(0mg·L-1). Its growth rate、photosynthetic pigment contents、SOD activities and MDA contents were measured after 96h exposure. Results showed that,DBP had inhibition effect on growth of S. obliquus compared with the control. With the increase of concentrations,the inhibition increased correspondingly. The 24,48,72,and 96h EC50 values of DBP were 3.31,15.49,1.95,and 2.21mg·L-1,respectively. DBP had the same effects on the contents of the chlorophyll-a,chlorophyll-b and carotenoids,that is,the contents of the photosynthetic pigments increased at the low concentrations(5~10mg·L-1)and decreased at the high concentrations(10~100mg·L-1). SOD activities of S. obliquus were stimulated first and inhibited later with the increase of DBP concentrations,and reached its peak when DBP concentration was 20mg·L-1(compared with the control,p<0.05). With the increase of DBP concentrations,MDA contents increased significantly(compared with the control,p<0.05,p<0.01),when DBP concentrations were higher than 10mg·L-1.