基于综合生物标志物响应指数评价0~#柴油和平湖原油胁迫下的缢蛏(Sinonovacula constricta)毒性效应

选择0#柴油和平湖原油乳化液对缢蛏(Sinonovacula constricta)进行氧化胁迫实验,选取典型的抗氧化酶-超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷光甘肽硫转移酶(GST)及过氧化物酶(POD)用于衡量油类污染物对生物体造成的氧化压力大小.此外,结合综合生物标志物响应(Integrated Biomarker Responses,IBR)指标,对2种石油污染物对缢蛏的毒性响应进行定量化评价.结果表明,不同浓度的0#柴油和平湖原油对缢蛏消化腺中的4种酶表现出不同程度的诱导效应,各试验组在暴露前期均表现出诱导或抑制,但对4种酶的影响存在时间顺序性,SOD、CAT和GST的酶活性表现为升高-降低的过程,POD表现为降低-升高的过程,活性达到峰值的时间SOD和CAT要早于GST和POD.结合计算出的IBR数值来看,高浓度0#柴油能够引起最为显著的生物效应变化,显示该石油污染物高毒性的特征,0#柴油生物毒性大于平湖原油生物毒性.

Investigation of toxic effects of No.0 fuel oil and Pinghu crude oil on Sinonovacula constricta by using integrated biomarker responses

We study the oxidant stress induced by the two oil pollutants (No.0 fuel oil and Pinghu crude oil) on Sinonovacula constricta. Hereafter, toxic difference was compared to capture more detailed condition about virulence variation. Activities of SOD, CAT, GST and POD were used to measure the impact of the oil pollutants. Furthermore, integrated biomarker responses (IBR) were employed to evaluate the toxicity differences. The main contents and the corresponding conclusions were as follows: Different concentrations of No.0 fuel oil and Pinghu crude oil had an induction effect on four enzymes of digestive glands.We found that SOD, CAT, GST, and POD levels displayed different variation trend following the prolonged duration. The outcomes indicated that the activities of SOD, CAT and GST in digestive glands showed an increase-decrease trend with increased exposure time. The activities of POD showed a decrease-increase trend with increased exposure time, and time for the enzymes to gain their highest activities varied with the four kinds of antioxidant enzymes. The activity of SOD and CAT reached the highest on the 3^rd day of exposure, with GST and POD on the 7^th day of the test. With calculated integrated biomarker response (IBR), the toxicity order was tentatively proposed as: No.0 fuel oil >Pinghu crude oil.