四环素胁迫对羊角月牙藻生长及抗氧化系统的影响

为探究四环素对藻类产生的毒性效应,选择羊角月牙藻(Selenastrum capricornutum)作为受试生物,采用室内试验方法,研究不同质量浓度的四环素(0,0.2,0.4,0.8,1.6,3.2 mg/L)对羊角月牙藻的生长抑制情况、叶绿素a含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量及活性氧(ROS)水平的影响。结果表明:四环素对羊角月牙藻的生长具有抑制作用,96 h半数效应浓度(EC_(50))为3.142 mg/L;四环素抑制了羊角月牙藻细胞中的叶绿素a含量;试验96 h时,随着四环素浓度的增大,羊角月牙藻细胞的SOD活性呈现先升高后降低的趋势,MDA含量、ROS水平均表现为升高趋势。因此,四环素可胁迫羊角月牙藻产生氧化应激反应,损害藻体的抗氧化系统,对水生生态系统具有潜在风险。

Effects of tetracycline on growth and antioxidant system of Selenastrum capricornutum

In order to study the toxic effects of tetracycline on algae, Selenastrum capricornutum is selected as the test organism. The growing situation, chlorophyll a contents, superoxide dismutase (SOD) activity, malondialdehyde (MDA) content and reactive oxygen species (ROS) level in the cells of Selenastrum capricornutum after 0, 02, 04, 08, 16, 32 mg·L^-1 tetracycline exposured are studied by indoor test method. The results show that the tetracycline can strongly inhibit growth of Selenastrum capricornutum and the 50% effective concentration (EC₅₀) is 3.142 mg·L^-1 during 96 h exposured. Tetracycline treatment inhibits the content of chlorophyll a in the cells of Selenastrum capricornutum. During 96 h exposure period, with the increase of tetracycline concentrations, the activity of SOD shows a "Bell-shaped" trend, the content of MDA and the level of ROS shows an upward trend. The study indicates that tetracycline can cause oxidative stress and damage the antioxidant system in Selenastrum capricornutum cells. Tetracycline poses a potential risk to aquatic ecosystems.