[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, EC99 were 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 EC20 and 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.