[C_8mim]Br对聚球藻7942生长及生理特性的影响

Effects of 1 - octyl - 3 - methylimidazolium bromide ( [C_8 mim]Br) on the growth and physiological characteristics of Synechococcus sp. PCC 7942

为了研究离子液体对微藻生长及生理特性的影响,以聚球藻7942(Synechococcus sp.PCC 7942)为实验材料,分析1-辛基-3-甲基咪唑溴盐(1-octyl-3-methylimidazolium bromide;[C8mim]Br)对其生长及生理特性的影响。结果表明:(1)[C8mim]Br严重抑制聚球藻的生长,这种抑制作用可能是由藻细胞膜被破坏引起的。(2)低浓度[C8mim]Br可诱导藻细胞合成超氧化物歧化酶(Superoxide dismutase,SOD)等可溶性蛋白,抵御[C8mim]Br的胁迫;但高浓度[C8mim]Br又会使SOD等酶活力降低。(3)随着[C8mim]Br浓度的升高,藻细胞中丙二醛(Malondialdehyde,MDA)含量显著增加,表明细胞中活性氧自由基(Reactive oxygen species,ROS)过量积累,这将破坏聚球藻的细胞膜结构与功能,使细胞遭受严重损伤。因此,[C8mim]Br可通过破坏藻细胞膜的结构与功能,导致细胞变形、分裂,从而影响藻细胞的生长繁殖,这将为探讨[C8mim]Br的毒性效应机制及其环境风险评价提供数据资料和科学依据。

The growth and physiological characteristics of Synechococcus sp. PCC 7942 under different 1 - octyl- 3 -methylimidazolium bromide （[ C8mim] Br） concentrations were analyzed to exploit the effects of i- onic liquids on microalgae. The results showed that [ C8mim ] Br had a significant inhibition effect on the growth of Synechococcus sp. PCC 7942 ,which may be due to the destruction of microalgal cell membrane. Low concen- trations of [ C8mim] Br would induce the synthesis of soluble protein, such as superoxide dismutase （SOD）, which played an important role in the defense mechanism to protect cells from [ C8miml Br stresses;but high concentrations of [ C8mim] Br would cause the inactivation of SOD and decrease the protein contents. Moreo- ver,malondialdehyde （MDA） contents in Synechococcus sp. PCC 7942 were enhanced with the increase of[ C8 mim ] Br concentrations, showing that excessive accumulation of reactive oxygen species （ROS） damaged the structure and function of microalgal cell membrane. Therefore, under the stress of [ C8 mim ] Br, the structure and function of the microalgal cell membrane would be damaged by excessive ROS and [ C8mim] Br,which would lead to the inhibition of the microalgal growth. The results provide data for exploiting toxic mechanisms and evaluating environmental impacts of [ C8mim ] Br.