钙、镁离子在水流作用下对铜绿微囊藻生长的影响

为了解在"引江济太"过程中大量钙、镁离子的引入对铜绿微囊藻生长的影响,本实验在控制温度和光照条件下,室内模拟不同钙、镁离子浓度在两个特征流速5 cm/s和15 cm/s下微囊藻的生长。实验结果表明,微囊藻藻密度随钙、镁离子浓度的增加而增加,流速在15cm/s下微囊藻最大藻密度(9 236.4×104cell/mL)是流速为5 cm/s下最大藻密度(2 873.72×104cell/mL)的3倍,流速为15 cm/s下微囊藻最大比增长速率均较5 cm/s下的高。这可能是在水流产生的剪切力作用下藻细胞胞外多糖增加,粘附更多的钙、镁离子更利于钙、镁离子迁移到胞内,同时胞外附着的钙、镁离子尤其钙离子形成桥联,使微囊藻细胞形成群体产生微环境利于微囊藻的生长。水流对微囊藻利用钙、镁离子有重要的影响,这为有效调水抑制蓝藻生长提供科学依据。

Effects of Calcium/Magnesium Ions on Growth of Microcystis aeruginosa under Water Flow

Calcium and magnesium are important nutrients element in growth and reproduction of algae.To understand the introduction of calcium and magnesium on the growth of M.aeruginosa in the process of river water transferring in Taihu Lake,the experiment was done by setting different concentrations under water flow of 5cm/s and 15 cm/s.Results showed that the density of M.aeruginosa increased with ions concentration,the maximum algae density was about 9,236.4×104 cell/mL at 15 cm/s,which was three times at 5 cm/s about 2,873.72×104 cell/mL,and the maximum specific growth rate of M.aeruginosa at 15 cm/s was higher than 5cm/s,the reason may be extracellular polysaccharides of cells increased under low shear,and adhered more calcium and magnesium which migrate into cellular,and especially calcium ions forms a bridge in cell formed colony,which produced microenvironment conductive to growth of algae.Water flow has significant impact on M.aeruginosa utilizing calcium and magnesium,which would effectively transfer water to restrain growth of M.aeruginosa.