聚苯乙烯纳米塑料对铜绿微囊藻生长的毒性效应OA

[Objective]This paper investigates the effects of polystyrene nanoplastics(PS-NPs)on the growth of Microcystis aeruginosa,understands the stress and toxic effects of PS-NPs on Microcystis aeruginosa,and provides theoretical basis for the protection and restoration of freshwater ecosystems.[Methods]This paper conducted cultivation experiments on Microcystis aeruginosa using culture medium containing different concentrations of PS-NPs,and analyzed the growth,photosynthetic characteristics,antioxidant system,and cell surface morphology of Microcystis aeruginosa by PS-NPs.[Results]Under the 15 day exposure experiment,it was positively correlated with the concentration of PS-NPs for the growth rate,photosynthetic efficiency,and oxidative damage intensity of Microcystis aeruginosa.The inhibition rate was over 70％of chlorophyll-a(Chl-a)concentration when the concentration was more than 50 mg/L of PS-NPs on the 10th day of the experiment.PS-NPs mainly reduced the efficiency of algal cell light energy utilization and photosynthesis by inhibiting the electron transfer of algal photoreaction,and led to the accumulation of malondialdehyde(MDA)and lipid peroxidation in algal cells.Scanning electron microscopy revealed that PS-NPs could aggregate on the surface of algal cells and cracks.Especially at higher concentrations.[Conclusion]PS-NPs could limit the normal transfer of energy by inhibiting the electron transfer in algal photoreaction,thereby affecting the normal growth of algae at higher concentrations.PS-NPs can promote reactive oxygen species in Microcystis aeruginosa,thereby disrupting its physiological balance.PS-NPs are prone to heterogeneous aggregation with algal cells,leading to surface structure disorder and deformation.