对一株从野外分离得到的铜绿微囊藻产毒株进行分批培养，在不同的氮磷条件下研究其生长、光合荧光及毒素含量的变化。结果表明：正磷酸盐浓度不变时，铵氮浓度的改变对铜绿微囊藻的生长有明显影响。叶绿素a(Ch1.a)含量在铵氮浓度为1 83-l8.3mg/L时明显较大；微囊藻毒素(包括MC-LR和MC-RR)的含量在铵氮浓度为1 83mg/L时达到最大；当铵氮浓度为0-1.83mg／L时，随着铵氮浓度升高，可变荧光Fv和MC的产量均增大，同时MC异构体的种类增多；铵氮浓度过大对M. aeruginosa的生长、生理和产毒均有抑制作用。在另一组实验中，即铵氮浓度不变而正磷酸盐浓度增大时，Ch1.a含量呈总体下降的趋势，并且与Fv／Fm 呈显著正相关关系(P<0．01，r=0.97)，MC(MC-LR和MC-RR)的含量在正磷酸盐浓度小于0.56mg／L时明显升高，MC-LR与Fv／Fm 呈显著正相关关系(P<0.01，r=0.967)。

Most of the cyanophages were adsorbed onto the ultrafilter membrance when pre-filtrated water sample passed through the tangential flow ultrafiltration system. In order to recover much more cyanophages, we used a technique named "backflushing ultrafiltration". The results indicated that when the volume of the backflush liquid was raised step by step, the concentration multiple of the cyanophage would gradually decrease, while the recovery rate of the cyanophage would gradually increase. In our performance, the maximal concentration multiple and the recovery rate of cyanophage could reach up to 30 times and more than 90% severally. This method was tested to be effective for concentrating cyanophage from large volume liquid sample. Moreover, the concertration multiple of the cyanophage could be elevated to nearly one-hundred times when two-step backflushing ultrafiltration was adopted