大漂化感物质对铜绿微囊藻生长及藻毒素产生和释放的影响

Using of aquatic plants which can produce secondary metabolites (allelochemicals) to inhibit the algae growth has important environmental and ecological significance. In this study, one kind of large floating aquatic plants named Pistia stratiotes Linn., which has high effciency on nitrogen and phosphorus removal from water, is taken as the allelochemicals-extracted material in order to study the influences of allelochemicals on the inhibition of Microcystis aeruginosa growth, and on the production and release of microcystins(MC-LR). The objects of this study mainly include establishment and improvement of the methods of allelochemicals separation and extraction, confirmation of the best using concentration, indicating the activity of alga growth inhibition and the influence on the production and release of MC-LR. The implementation of this project not only can improve the using and extraction efficiency of allelochemicals from aquatic plants for alga growth inhibition, it also can provide scientific reference for the analysis of the ecological security of practical application of aquatic plants algal allelopathic substances in the future.

利用水生植物产生的次生代谢物质(化感物质)抑制藻类的生长具有重要的环境和生态意义。本项目以高效脱氮除磷漂浮植物-大漂（Pistia stratiotes Linn.）作为化感物质的提取材料，研究大漂化感物质对铜绿微囊藻生长及微囊藻毒素（MC-LR）产生和释放的影响规律，主要研究内容包括建立和完善大漂化感物质的高效分离提取方法、确定大漂化感物质的最佳投放浓度、说明大漂化感物质对铜绿微囊藻的抑藻活性、阐明大漂化感物质对铜绿微囊藻MC-LR产生和释放的影响规律。项目实施不仅可以有效提高水生植物抑藻化感物质的提取利用效率，也可为今后水生植物抑藻化感物质的实际应用生态安全性分析提供科学借鉴和参考。

利用水生植物产生的次生代谢物质(化感物质)抑制藻类的生长具有重要的环境和生态意义。本项目研究了大漂化感物质的提取方法的优化、最佳抑藻浓度范围的确定，及其对铜绿微囊藻生长及微囊藻毒素（MC-LR）产生和释放的影响。通过测定藻细胞密度和叶绿素a含量的变化，表明以乙酸乙酯为提取溶剂、1 : 20 g/mL为提取比例、提取时间为1h，获得的化感物质抑藻效果最佳，Ec50,7d为最低值65 mg/L。通过优化方法提取获得的大漂化感物质的最佳抑藻浓度范围为60～100 mg/L，藻细胞培养3～7d内相对抑制率（IR%）达50%～90%，叶绿素a含量减少50%～75%。同时发现整个培养期间，大漂化感物质对MC-LR的胞外释放无显著影响。培养7d后，单位藻细胞内MC-LR的含量随大漂化感物质浓度的增加而升高，16d后无显著影响。藻细胞培养液中MC-LR总量不会增大。由此可知，使用大漂化感物质抑制铜绿微囊藻，在有效控制藻细胞增殖的同时不会促进藻毒素的释放，生态安全性高，可应用至实际水体水华处理中。