Phytoremediation of a mixture of toxic cyanobacteria. Does phytoplankton composition affect the amount of toxins removed?

Phytoremediation is an environmentally friendly method for removing harmful cyanotoxins from water. The main objective of the study was to test whether the presence of several cyanobacteria at the same time in the medium together with a macrophyte would affect its ability to phytoremediate cyanotoxins. Analyses using highperformance liquid chromatography indicated that the presence of the plant in all cases caused a significant reduction in the intracellular pool of toxins and cyanobacterial biomass. The addition of the plant to the cyanobacterial mixture after 14 days resulted in a 0.99-1.59-fold reduction in the intracellular pool of anatoxin-a (ATX-a). At the same time, the concentration of the toxin in the medium decreased 0.23 times during the co cultivation of Dolichospermum flos-aquae/Micorcystis aeruginosa and increased from 0.10 to 1.30-fold in the presence of Raphidiopsis raciborskii. During the experiments, the plant showed the ability to take up ATX-a from the medium (from 40% to 70% of the total pool). The plant reduced the intracellular cylindrospermopsin content from 0.54 to 0.92-fold, while increasing the release of the toxin into the medium from 0.39 to 4.23-fold. The plant was equally effective in reducing the amount of intracellular microcystin-LR by 1.00-1.37 times, while leading to the release of the toxin into the medium. The increase in the amount of toxin in the medium ranged from 0.94 to 28.86 times. Based on the obtained results, it can be concluded that the plants' efficiency of cyanotoxins phytoremediation varies significantly depending on the cyanobacteria composition in mixed culture.

Automated summary

Phytoremediation is a useful method for removing cyanotoxins from water, but its efficacy is influenced by the composition of cyanobacterial mixtures. This study found that while some plants can effectively reduce intracellular toxins and cyanobacterial biomass, they can also cause an increase in toxin concentration in the medium.