铜绿微囊藻对Cd~(2+)胁迫的生理生化响应

为探讨重金属离子Cd~(2+)对铜绿微囊藻的毒性效应,通过室内实验,研究了铜绿微囊藻在不同Cd~(2+)浓度胁迫下的生理生化变化。结果表明:1 Cd~(2+)对铜绿微囊藻具有明显的毒害作用,Cd~(2+)对铜绿微囊藻的24hEC_(50)、48h-EC_(50)、72h-EC_(50)、96h-EC_(50)分别为0.978,0.863,0.646,0.302 mg/L,随着作用时间的延长,EC_(50)显著降低(P0.05);2在Cd~(2+)胁迫下,铜绿微囊藻的光合生理特性受到不同程度的影响,叶绿素荧光特性Fv/Fm、YⅡ]、ETR、q P变化趋势基本一致,且与叶绿素a都表现出剂量-效应关系;3 Cd~(2+)诱导藻细胞产生氧化应激反映,其中丙二醛(MDA)和超氧化物歧化酶(SOD)活性均显著升高(P0.05),且随暴露时间延长,氧化应激强度增大。综上,重金属离子Cd~(2+)能够抑制铜绿微囊藻的生长,阻碍其光合作用,同时造成氧化应激效应。

Physiological and biochemical responses of Microcystis Aerugionosa to Cd2+

To explore the toxic effect of Cd2+ to Microcystis Aerugionosa, the laboratory test was conducted to study its physio-logical and chemical changes under different levels of Cd2+. The results show that:(1) Cd2+ has significant toxic effects on Mi-crocystis aerugionosa, the 24h-EC50、48h-EC50、72h-EC50、96h-EC50 are 0. 978, 0. 863, 0. 646 mg/L and 0. 302 mg/L re-spectively, and EC50 significantly reduces with time ( P <0. 05);(2) Under the stress of Cd2+, the photosynthetic physiologi-cal characteristics of Microcystis aeruginosa are affected, the chlorophyll fluorescence characteristics Fv/Fm, YII], ETR, qP trends to be consistent with chlorophyll a and shows a dose-response relationship;(3) Cd2+ induces oxidative stress, in which MDA content and SOD activity are significantly increase ( P <0. 05), and with prolonged exposure, the oxidative stress intensity increases. Therefore, it is concluded that Cd2+ could inhibit the growth of Microcystis aerugionosa, hinder photosynthesis and cause oxidative stress.