Generation and Release of Microcystin-LR by Microcystis aeruginosa Under Hydroquinone Inhibition

The generation and release of algal toxin Microcystin-LR( MCLR),as well as the intracellular organic chemicals were studied during the inhibition processes of Microcystis aeruginosa using hydroquinone as the inhibitor. According to the dose-effect relationship,the corresponding dosages of EC20,EC50,EC70,EC90,EC99were added to the algae suspension. The TOC was determined by the total organic carbon analyzer,and the three-dimensional fluorescence spectrum was obtained by the fluorescence spectrophotometer. The results showed that the generation of MCLR was inhibited at EC20and the total MCLR was 72. 4%-83. 0% of the control samples. Whereas the cells were stimulated to produce higher amount of MCLR,and the total MCLR was 1. 77-3. 13 times as high as that of the control samples at EC50-EC99. The intracellular MCLR was largely released to the water at EC70-EC99. The release of other intracellular organic chemicals mainly referred to humic-like and fulvic-like substances,which were unstable and had an obvious degradation and transformation after 6 days of cultivation.