The ecological risks of hydrogen peroxide as a cyanocide: its effect on the community structure of bacterioplankton

【摘要】 Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide（H₂O₂） is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H₂O₂ has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H₂O₂ on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by M icrocystis at a highly eutrophic Dianchi Lake, China. The results showed that M icrocystis was more sensitive to H₂O₂ than other eukaryotic algae. More interestingly, application of H₂O₂ changed the community structure of bacterioplankton, evidenced by the emergence of F irmicutes as the dominant species in place of B acteroidetes and Proteobacteria. The H₂O₂ treatment resulted in the community of bacterioplankton that was primarily dominated by E xiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H₂O₂ reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H₂O₂ to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment.更多还原

【Abstract】 Microcystis blooms are an environmental and ecological concern that has received a serious attention. Hydrogen peroxide（H₂O₂） is an environment-friendly cyanocide that is commonly used to control Microcystis blooms. While the ecological safety of H₂O₂ has been previously studied, its influence on bacterioplankton has not been investigated to date. In this study, we used mesocosm experiments to determine the influence of H₂O₂ on the dynamic changes of the community structure of bacterioplankton. By using deep-sequencing and metagenomics strategy we determined the community structures of phytoplankton and bacterioplankton assemblages that were dominated by M icrocystis at a highly eutrophic Dianchi Lake, China. The results showed that M icrocystis was more sensitive to H₂O₂ than other eukaryotic algae. More interestingly, application of H₂O₂ changed the community structure of bacterioplankton, evidenced by the emergence of F irmicutes as the dominant species in place of B acteroidetes and Proteobacteria. The H₂O₂ treatment resulted in the community of bacterioplankton that was primarily dominated by E xiguobacterium and Planomicrobium. Our results show that the abundance changed and the bacterioplankton diversity did not recover even after the concentration of H₂O₂ reached to the background level. Thus, the response of bacterioplankton must be considered when assessing the ecological risks of using H₂O₂ to control Microcystis blooms, because bacterioplankton is the key player that forms the basis of food web of aquatic environment.更多还原