氮、磷、铁、锌对铜绿微囊藻生长及产毒的影响

为探讨氮、磷、铁、锌对铜绿微囊藻生长及产毒的影响，以HGZ为基础培养基，调整氮、磷、铁、锌的浓度，于无菌条件下对两种藻株进行培养，定期取培养液进行细胞计数及用ELISA方法测定微囊藻毒素的含量。结果表明，浓度的改变没有引起无毒株产生毒素，也没有改变产毒株的产毒特性。高浓度的氮(1.6～245.1mg/L)有利于两藻株的生长及产毒株的毒素合成，而对磷、铁、锌的需求量较低。当磷的浓度低于1.4mg/L时，无毒株随其浓度增加而生长加快，但浓度超过此范围，则变化不大。产毒株的生长和产毒对磷盐的浓度变化不敏感，过高浓度的磷(62.1mg/L)可抑制其生长。两藻株的生长对铁、锌浓度的变化也不敏感，但产毒株的毒素合成却随铁离子浓度升高而缓慢上升。在氮、磷、锌3个单因素研究中，培养液中藻细胞的数量与总毒素含量均呈正相关(P＜0.05)，而铁未呈相关关系。

Effects of Nitrogen, phosphorus, lron and Zinc on Growth of and MicrocystinProduction of Microcystis aeruginosa Strains

In order to understand the effects of nitrogen, phos- phorus, iron and zinc on the growth of and hepatoxin production by Microcystis aeruginosa strains, strains were cultured in the serious sterilized mediums in which concentrations of nitrogen, phosphorus, iron, zinc were changed on the base of HGZ medium respectively. Growth was determined by cell counting, while toxin was analyzed by ELISA method. The results showed that alterations of contents of nitrogen, phosphorus, iron and zinc in the medium did not induce toxin formation by NIES-101 strain, nor did toxic NIES-90 strain lose its ability to produce toxin. High nitrogen concentration (test range, 1.6mg/L to 245.1mg/L) favored both growth of and toxin production by NIES-90 strain. Growth of NIES-101 strain depended on phosphorus concentration at low levels of phosphorus (0.3mg/L to 1.4mg/ L) and higher concentrations had no additional effect. However, Relatively lower level of phosphorus, iron, zinc were needed for growth and toxin production. Growth of and toxin production by NIES-90 strain weren' t sensitive to phosphorus concentration that was less than 62.1mg/L, which was also seen in the iron and zinc experiments, but toxin concentration raised slowly with increasing of iron concentration. In three single-factor nitrogen, phosphorus, zinc, total toxin expressed as ng/L was positively correlated with algae cell number, but was not seen in the iron experiment.