柴油水溶性组分对鼠尾藻和孔石莼生长及抗氧化酶的影响

Effect of Diesel Water Accommodated Fraction on Growth and Antioxidant Enzymes of Sargassum thunbergii and Ulva pertusa

为探究石油烃类对大型海藻生长及抗氧化酶应答机制的影响,并为利用藻类修复石油烃污染水域提供科学依据,本文以鼠尾藻(Sargassum thunbergii)和孔石莼(Ulva pertusa)为研究对象,探讨了不同浓度的柴油水溶性组分对大型海藻生长、净光合速率、呼吸速率以及生化指标的影响。研究显示,鼠尾藻在柴油水溶性组分浓度为8.599、25.770和41.285 mg/L处理组中的相对生长率(RGR)高于对照组,85.990 mg/L处理组中生长出现显著抑制现象。在24 h内,各浓度处理组的孔石莼RGR显著高于对照组,72 h后,41.285和85.990 mg/L处理组的孔石莼RGR显著降低。两种藻的净光合速率和叶绿素a含量在各浓度处理组中的变化趋势与其RGR相对应,而呼吸速率在各浓度处理组中要高于对照组。高浓度的柴油水溶性组分均引起两种藻的丙二醛含量上升。鼠尾藻的超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性分别在96和48 h显著上升,过氧化物酶(POD)活性变化不显著,总抗氧化能力在96 h达到最高值。孔石莼的SOD、CAT和POD活性分别在48、72和48 h上升,总抗氧化能力在48 h达到最高值。实验结果表明,两种海藻对柴油水溶性组分的耐受性不同,但柴油水溶性组分对两种海藻的生长和生化组分的影响呈相同的变化趋势,“低促高抑”现象明显。

To explore the effect of petroleum hydrocarbons on the growth and antioxidase response mechanism of macroalgae and provide a scientific basis for using algae to repair petroleum hydrocarbons-contaminated waters,the effects of water-accommodated fraction of 0#diesel(diesel-WAF)on the relative growth rate(RGR),net photosynthesis rate,respiration rate and biochemical components of Sargassum thunbergii and Ulva pertusa were studied.The results showed that RGRs of S.thunbergii were higher than those of control at lower diesl-WAF concentrations(8.599 mg/L,25.770 mg/L and 41.285 mg/L),the growth of S.thunbergii was significantly inhibited at the highest diesl-WAF concentration(85.990 mg/L).The RGRs of U.pertusa were increased within 48 hours but significantly decreased in 41.285 and 85.990 mg/L treatment groups after 72 hours.The changes of net photosynthetic rates and the contents of chlorophyll a in treatment groups were corresponding to their changes of RGRs.Compared with the control group,the respiration rates of the two algae were increased.High concentration of diesel-WAF caused the increase of malondialdehyde(MDA)content in two algae.The activities of superoxide dismutase(SOD)of S.thunbergii raised in 96 h and catalase(CAT)in 48 h while peroxidase(POD)did not vary obviously.The total antioxidant capacity(T-AOC)reached the highest value at 96 h.The activities of SOD,CAT and POD of U.pertusa increased separately in 48,72 and 48 h.The T-AOC reached the highest value at 48 h.The results indicated that the tolerance of two algae to the diesel-WAF was different,however,the identity is shown in the change trend of the growth and biochemical components of two algae under the diesel-WAF stress.