多环芳烃在赤潮微藻光合作用中所起作用的研究

Study on the Effects of Polycyclic Aromatic Hydrocarbons on the Photosythesis in Red Tide Microalgae

采用实验生态学的方法,研究了3种多环芳烃-菲、芘和蒽对3种赤潮微藻-赤潮异弯藻、亚历山大藻和中肋骨条藻光合速率的影响。结果表明:较低浓度的菲、芘和蒽处理使3种赤潮微藻的光合速率有所提高,而较高浓度处理则降低了藻细胞的光合速率。3种多环芳烃-菲、芘和蒽胁迫对赤潮异弯藻光合速率的96h·EC50分别为0.089、0.110和0.124mg·L-1,对中肋骨条藻的96h半抑制剂量分别为0.103、0.127和0.138mg·L-1,对亚历山大藻的96h半抑制剂量分别为0.116、0.131和0.141mg·L-1,说明3种多环芳烃对赤潮微藻均表现出一定的毒性效应,其中菲的毒性作用最强。UV-B辐射(0.3J·m-2的辐射剂量)和多环芳烃的联合作用一方面增强了菲、芘和蒽对3种赤潮微藻光合效率的抑制作用,导致光合速率明显降低,另一方面在一定程度上改变了3种多环芳烃毒性作用的强弱,使芘的毒性作用变得最强。

The photosynthesis responses of Heterosigma akashiwo,Skeletonema costatum and Alexandrium tamarense Balech to polycyclic aromatic hydrocarbons（PAHs）exposure treatment was studied by experimental ecology methods.The results showed that lower concentration of phenanthrene,pyrene and anthracene could promote the photosynthesis of Heterosigma akashiwo,Skeletonema costatum and Alexandrium tamarense Balech.However,higher concentration of phenanthrene,pyrene and anthracene exhibited inhibition to photosynthesis rate.The 96h·EC50values of phenanthrene,pyrene and anthracene treatment to photosynthesis of Heterosigma akashiw were 0.89,0.110 and 0.124mg·L-1 respectively,and that to Skeletonema costatum were 0.103,0.127 and 0.138mg·L-1 and to Alexandrium tamarense Balech were 0.116,0.131 and 0.141mg·L-1.The results indicated that three kinds of polycyclic aromatic hydrocarbons exhibited certain toxicity to red tide microalgae,and toxicity of phenanthrene was strongest.The combination of 0.3J·m-2 UV-B radiation and polycyclic aromatic hydrocarbons intensified the inhibition to photosynthesis rate,which declined more significantly than single exposure in polycyclic aromatic hydrocarbons in three species of red tide microalgae.On the other hand,it changed the three PAHs toxicity in a certain extent,which was strongest in pyrene.