Ecology

Bacteria

Biology

Microcystis

Microcystin

Microcystis aeruginosa

Cyanobacteria

Cyanotoxin

Genetics

Environmental chemistry

Microbiology

Chemistry

Nutrient

Eutrophication

Environmental Science & Technology

Although the fate of nanoplastics (<100 nm) in freshwater systems is increasingly well studied, much less is known about its potential threats to cyanobacterial blooms, the ultimate phenomenon of eutrophication occurrence worldwide. Previous studies have evaluated the consequences of nanoplastics increasing the membrane permeability of microbes, however, there is no direct evidence for interactions between nanoplastics and microcystin; intracellular hepatotoxins are produced by some genera of cyanobacteria. Here, we show that the amino-modified polystyrene nanoplastics (PS-NH2) promote microcystin synthesis and release from Microcystis aeruginosa, a dominant species causing cyanobacterial blooms, even without the change of coloration. We demonstrate that PS-NH2 inhibits photosystem II efficiency, reduces organic substance synthesis, and induces oxidative stress, enhancing the synthesis of microcystin. Furthermore, PS-NH2 promotes the extracellular release of microcystin from M. aeruginosa via transporter protein upregulation and impaired cell membrane integrity. Our findings propose that the presence of nanoplastics in freshwater ecosystems might enhance the threat of eutrophication to aquatic ecology and human health.

Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial <i>Microcystis aeruginosa</i>

Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa