1,2,4-三氯苯对斜生栅藻的毒性效应及其机制研究

Toxic Effects and Mechanisms of 1,2,4-Trichlorobenzene on Scenedesmus obliquus

以1,2,4-三氯苯(1,2,4-TCB)处理后斜生栅藻的生长状况、蛋白质含量、叶绿素含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性、丙二醛(MDA)含量和培养液总有机碳(TOC)含量的改变来检测1,2,4-TCB对斜生珊藻的毒性效应及其毒性作用机制。结果表明,1,2,4-TCB对斜生栅藻的生长有一定的抑制作用,表现出一定的浓度和时间依赖性;1,2,4-TCB处理4d后,斜生栅藻细胞蛋白质含量下降,10mg·L^(-1)和15mg·L^(-1)1,2,4-TCB处理后,藻细胞中可溶性蛋白质含量比对照组分别下降了62.89%和80.22%,叶绿素a,b和总叶绿素含量下降,叶绿素a含量下降最显著,在5mg·L^(-1)处理组即表现出显著的统计学差异;膜结合酶SOD和POD活性降低,15mg·L-1TCB组藻细胞的SOD和POD活性分别是对照组的40.57%和77.42%;脂质过氧化产物MDA含量升高,培养液中TOC含量升高,其中10mg·L^(-1)和15mg·L^(-1)1,2,4-TCB处理组TOC含量分别比对照组高57.95%和72.55%。这表明1,2,4-TCB对斜生栅藻的生长及各种生理功能产生毒害效应,其作用机制可能与藻细胞生物膜通透性和生物膜及其他生物大分子的脂质过氧化有关。

Toxic effects of 1,2,4-trichlorobenzene （1,2,4-TCB） on Scenedesmus obliquus were studied through investigating the growth, the content of protein and the content of chlorophyll. The toxic mechanisms of 1,2,4-TCB were analyzed by determining the SOD and POD activities, the content of MDA and TOC in the algae. The growth of algae was inhibited by 1,2,4-TCB in time-response and dose-response manners. Compared with the control, the content of soluble protein in S. obliquus decreased by 62.89% and 80.22%, respectively, after treated with 10 mg· L^-1 and 15 rag· L^-1 1,2,4-TCB. The contents of chlorophyll a, b and total chlorophyll, especially the content of the chlorophyll a, decreased significantly when treated with 1,2,4-TCB for 4 d. The activities of SOD and POD decreased 40.57% and 77.42% than those of the control, respectively. The content of MDA increased in dose-response manners. Furthermore, the content of TOC in the culture with 10 mg· L^-1 and 15 mg· L^-1 1,2,4-TCB increased 57.95% and 72.55%, respectively. These results suggested that 1,2,4-TCB affected the physiological activities ofS. obliquus, and the toxic mechanism was related to the permeability of cellular membrane and the lipidperoxidation of other organic macromolecules of S. obliquus cells.