中文摘要：

应用细胞计数法结合流式细胞术探讨了L-苯丙氨酸对铜绿微囊藻生长的作用与可能机制．结果表明：作用24h后，较低浓度L．苯丙氨酸（0．078～0．312μg／mL）对藻细胞生长表现为促进作用，而在较高浓度（0．625～20μg／mL）时表现为抑制作用．L-苯丙氨酸对铜绿微囊藻生长的抑制作用存在剂量效应和时间效应关系．24h生长抑制作用的Ic50为6．2μg／mL（95％可信区间是0．005～16．76μg／mL）．用L-苯丙氨酸染毒24h后，藻细胞膜完整性受到明显影响，而在48h后，细胞酯酶活性才发生改变．研究结果提示L-苯丙氨酸对铜绿微囊藻的生长存在hormesis效应并具有控藻作用，其控藻作用机制可能与L-苯丙氨酸导致藻细胞膜完整性受损和酯酶活性改变有关．

英文摘要：

The effects and possible mechanisms of action of L- phenylalanine on the growth of Microcystis aeruginosa cells were explored by cell counting and flow cytometry assays. L- phenylalanine promoted the growth of Microcystis aeruginosa at concentrations between 0.078 and 0. 312 μg/mL, but inhibited growth at concentrations between 0. 625 and 20μg/mL in 24 h exposure. The dose-effect and time-course relationships between exposure to L-phenylalanine and growth inhibition of Microcystis aeruginosa were observed. The IC50 value of L-phenylalanine for growth inhibition of Microcystis aeruginosa was 6. 2 μg/mL （95% confidence interval was 0. 005 to 16. 76 μg/mL）. The membrane integrity of the cells showed significant variations after 24 h exposure to L-phenylalanine. Meanwhile, no effects on esterase activity of the cells were observed until after 48 h exposure to L-phenylalanine. In conclusion, L-phenylalanine has hormesis effects and algae control effects on Microcystis aeruginosa. The latter is closely related to alterations or disorders in the cell membrane and with variation of esterase activity in the cells.