NaCl和Na_2SO_4盐胁对铜绿微囊藻生长影响的对比研究

Comparative study on the effect of NaCl and Na_2SO_4 salinity on the growth of Microcystis aeruginosa

利用实验模拟研究了NaCl和Na2SO4两种盐对铜绿微囊藻Microcystis aeruginosa生长的影响。通过向M11培养液中添加不同浓度的NaCl和Na2SO4,设定0.5、1、2、4 g·L-14个盐度梯度,研究NaCl和Na2SO4两种盐对藻细胞密度及叶绿素a的影响。实验结果表明,铜绿微囊藻可耐受2 g·L-1的NaCl和Na2SO4盐度胁迫,当盐度超过2 g·L-1后对微囊藻的生长起明显抑制作用。Na2SO4对藻密度及叶绿素a的影响较NaCl更显著。研究显示盐度可能是抑制咸水湖泊蓝藻水华发生的重要影响因素之一,因此制定我国西北地区湖泊富营养化控制标准时,建议应考虑盐的主要种类及盐浓度的影响。

The effect of NaCl and Na2SO4 salinity on the growth of Microcystis aeruginosa was estimated using simulated experiment. M11 cultures were tested with variable salinity concentrations （0.5, 1.0, 2.0 and 4.0 g·L-1） and the effects of salinity on the cell density and chlorophyll a were identified. The results demonstrated that M. aeruginosa could endure osmotic pressure of 2.0 g·L-1 salinity, whereas the growth of M. aeruginosa was restrained under hyper-saline conditions with the salinity of above 2.0 g·L-1. Comparative study on the effects of salinity on the growth and chlorophyll contents of NaCl and Na2SO4 showed that the effect of Na2SO4 was more significant than that of NaCl. Accordingly, it can be concluded that salinity might be an essential determining factor which inhibited Cyanophyta blooms in saline lakes. Thus, it was suggested that the impacts of salt species and salinity on algae growth should be taken into account when developing eutrophication criteria and standard in northwest region of China.