人工模拟UV-B辐射对铜绿微囊藻(Microcystis aeruginosa)生长的影响

摘要

An experiment that Microcystis aeruginosa was exposed to short-term (0 -24h) simulated UV-B radiation was carried out to determine the effect of increased UV-B radiation on the phytoplankton growth in lakes, especially lakes in the mountain and plateau.By measuring the biomass, physiological and ultrastructural indices, the response of M.aeruginosa to UV-B radiation was analyzed.When the UV-B radiation exposure time reached to 1h, the M.aeruginosa began to die, but the protein concentration increased and chlorophyll-a concentration remained stable.When the UV-B radiation exposure time was less than 4h, the activity of superoxide dismutase (SOD) enzyme remained high, the cell membrane was in good condition, and the number of thylokoids and cyanophycin granules remained stable.When the UV-B radiation exposure time was more than 4h, chlorophyll-a concentration and the activity of SOD enzyme of M.aeruginosa started to rapidly drop.The UV-B continuous radiation exposure time reaching to 4h was the maximum resistance of M.aeruginosa.%选择我国蓝藻水华的优势藻类铜绿微囊藻,进行人工模拟UV-B辐射连续24h照射实验,测定铜绿微囊藻生物量、生理及超微结构指标,探讨湖泊特别是高原湖泊藻类生长对UV-B辐射增强的胁迫响应.结果表明,当辐射时间达到1h时,铜绿微囊藻便开始陆续死亡,但蛋白质含量增加,且叶绿素a浓度保持稳定;当辐射时间少于4h时,细胞内超氧化物歧化酶(SOD)始终保持较高活性,细胞膜保持基本完整,细胞内类囊体和蓝藻素颗粒数目保持稳定;当辐射时间超过4h后,微囊藻叶绿素a浓度和SOD酶活性等开始快速下降.研究表明,连续辐射4h是铜绿微囊藻可抗逆的极限.