We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
The photosynthetic toxicity of nano-polystyrene to Microcystis aeruginosa is influenced by surface modification and light intensity
Summary
Researchers found that amino-modified nanoplastics are more toxic to the cyanobacterium Microcystis aeruginosa than unmodified particles, and that high light intensity amplifies this toxicity by generating additional reactive oxygen species — including singlet oxygen and hydroxyl radicals — through interactions between visible light and the particle surface.
It is known that nanoplastics can cause membrane damage and production of reactive oxygen species (ROS) in cyanobacteria, negatively impacting their photosynthetic reactions and growth. However, the synergistic effect of light intensity on nanoplastics' toxicity to cyanobacteria is rarely investigated. Here, we investigated the impact of nano-polystyrene particles (PS) and amino-modified nano-polystyrene particles (PS-NH) on cyanobacterium Microcystis aeruginosa cultivated under two light intensities. We discovered that PS-NH was more toxic to M. aeruginosa compared to PS with more damage of cell membranes by PS-NH. The membrane damage was found by scanning electron microscope and atomic force microscopy. Under low light, PS-NH inhibited the photosynthesis of M. aeruginosa by decreasing the PSII quantum yield, photosynthetic electron transport rate and pigment content, but increasing non-photochemical quenching and Car/chl a ratio to cope with this stress condition. Moreover, high light appeared to increase the toxicity of PS-NH to M. aeruginosa by increasing its in vitro and intracellular ROS content. Specifically, on the one hand, high visible light (without UV) and PS-NH induced more in vitro singlet oxygen, hydroxyl radical and superoxide anion measured by electron paramagnetic resonance spectrometer in vitro, which could be another new toxic mechanism of PS-NH to M. aeruginosa. On the other hand, high light and PS-NH might increase intracellular ROS by inhibiting more photosynthetic electron transfer and accumulating more excess energy and electrons in M. aeruginosa. This research broadens our comprehension of the toxicity mechanisms of nanoplastics to cyanobacteria under varied light conditions and suggests a new toxic mechanism of nanoplastics involving in vitro ROS under visible light, providing vital information for assessing ecotoxicological effects of nanoplastics in the freshwater ecosystem.
Sign in to start a discussion.
More Papers Like This
Nanoplastics promote microcystin synthesis and release from cyanobacterial Microcystis aeruginosa.
Researchers showed that amino-modified polystyrene nanoplastics (PS-NH2) stimulate microcystin synthesis and release in the bloom-forming cyanobacterium Microcystis aeruginosa by inhibiting photosystem II and increasing membrane permeability. This is the first direct evidence linking nanoplastics to enhanced cyanotoxin production in freshwater blooms.
Nanoplastics Promote Microcystin Synthesis and Release from Cyanobacterial Microcystis aeruginosa
Researchers discovered that amino-modified polystyrene nanoplastics promote both the production and release of microcystin, a harmful toxin, from the cyanobacterium Microcystis aeruginosa. The nanoplastics inhibited photosynthesis, induced oxidative stress, and damaged cell membranes, which enhanced toxin synthesis and extracellular release. The findings suggest that nanoplastic pollution in freshwater ecosystems could worsen the threat of harmful algal blooms to aquatic ecology and human health.
Post-exposure recovery of Microcystis aeruginosa from nanoplastics stress: metabolic adaptation and damage resilience
Researchers exposed Microcystis aeruginosa cyanobacteria to polystyrene nanoplastics for 15 days, then transferred them to NP-free medium to study post-exposure recovery. Toxicity was concentration-dependent during exposure, and cells showed metabolic changes and only partial recovery after removal, suggesting persistent effects on cyanobacterial physiology.
Mechanistic study on the increase of Microcystin-LR synthesis and release in Microcystis aeruginosa by amino-modified nano-plastics.
This study examined how amino-modified nanoplastics increase production and release of the toxin Microcystin-LR in the cyanobacterium Microcystis aeruginosa, revealing the cellular and gene-expression mechanisms behind this enhancement. The findings highlight how nanoplastic pollution can amplify harmful algal bloom toxicity.
Micro- and nanoplastic stress intensifies Microcystis aeruginosa physiology and toxin risks under environmentally relevant water chemistry conditions
Researchers exposed the cyanobacterium Microcystis aeruginosa to environmentally relevant concentrations of micro- and nanoplastics, finding both significantly enhanced algal biomass and microcystin toxin production, with nanoplastics additionally promoting extracellular toxin release.