微电流电解对铜绿微囊藻(Microcystis aeruginosa)叶绿素荧光特性的影响

Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence of Microcystis aeruginosa

研究微电流电解不同电流密度下铜绿微囊藻(Microcystis aeruginosa)的叶绿素荧光参数变化,从藻类生理生态特征方面揭示电解抑藻的作用机理.结果表明:对于体积一定而初始细胞密度不同的铜绿微囊藻藻液,微电流电解抑藻存在相应的临界电流密度阈值,当电流密度>阈值时,藻的生长得到完全抑制.当电流密度<阈值时,藻的光系统Ⅱ受损,但经过6 d的培养其生理活性可恢复正常.若电流密度>临界值,电解胁迫将超过藻的耐受能力,从培养的第2 d开始藻的光系统Ⅱ功能完全丧失.电解抑藻一方面是通过破坏光系统Ⅱ和捕光天线藻胆体之间的连接,使藻胆体无法继续向光系统Ⅱ传递光能;另一方面是通过破坏藻细胞光系统Ⅱ结构,使其无法进行光合作用,最终导致藻细胞的死亡.

Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence of Microcystis aeruginosa were investigated in order to reveal the mechanisms of electrolytic inhibition of M. aeruginosa. Thresholds of electric current density were found under a certain initial algae cell density. When the current density was higher than the threshold density,the growth of algae was inhibited completely by electrolytic treatment,and the algae lose its ability to survive and to grow. The changes of chlorophyll fluorescence parameters demonstrated that when the algal solution was treated by current densities lower than the threshold density,PS II of algae was damaged by electrolysis,but it still maintained relatively high activity. The activity of algae recovered completely after 6 days＇ cultivation. Moreover,when algal solution was treated by current densities higher than the threshold density,the connection of phycobilisome and PS II core complexes were destroyed. PS II system of algae was damaged irreversibly,and algae could not survive thoroughly. The inactivation of M. aeruginosa by electrolysis can be attributed to irreversible separation of phycobilisome from PS II core complexes and the damage of PS II of M. aeruginosa.