We can't find the internet
Attempting to reconnect
Something went wrong!
Hang in there while we get back on track
Micro-/nano-plastics as vectors of heavy metals and stress response of ciliates using transcriptomic and metabolomic analyses
Summary
This study examined how polystyrene microplastics and nanoplastics interact with cadmium to affect single-celled marine organisms called ciliates. The combined exposure was more toxic than either pollutant alone, disrupting the organisms' metabolism and stress responses at the genetic level. The findings demonstrate that microplastics can make heavy metal pollution worse by carrying metals into cells, a concern for marine food web contamination that could ultimately affect seafood safety.
The escalating presence of microplastics and heavy metals in marine environments significantly jeopardizes ecological stability and human health. Despite this, research on the combined effects of microplastics/nanoplastics (MPs/NPs) and heavy metals on marine organisms remains limited. This study evaluated the impact of two sizes of polystyrene beads (approximately 2 μm and 200 nm) combined with cadmium (Cd) on the ciliate species Euplotes vannus. Results demonstrated that co-exposure of MPs/NPs and Cd markedly elevated reactive oxygen species (ROS) levels in ciliates while impairing antioxidant enzyme activities, thus enhancing oxidative damage and significantly reducing carbon biomass in ciliates. Transcriptomic profiling indicated that co-exposure of MPs/NPs and Cd potentially caused severe DNA damage and protein oxidation, as evidenced by numerous differentially expressed genes (DEGs) associated with mismatch repair, DNA replication, and proteasome function. Integrated transcriptomic and metabolomic analysis revealed that DEGs and differentially accumulated metabolites (DAMs) were significantly enriched in the TCA cycle, glycolysis, tryptophan metabolism, and glutathione metabolism. This suggests that co-exposure of MPs/NPs and Cd may reduce ciliate abundance and carbon biomass by inhibiting energy metabolism and antioxidant pathways. Additionally, compared to MPs, the co-exposure of NPs and Cd exhibited more severe negative effects due to the larger specific surface area of NPs, which can carry more Cd. These findings provide novel insights into the toxic effects of MPs/NPs and heavy metals on protozoan ciliates, offering foundational data for assessing the ecological risks of heavy metals exacerbated by MPs/NPs.
Sign in to start a discussion.
More Papers Like This
Physiological and transcriptomic responses of seawater halobios to micro/nano-scale polystyrene-cadmium exposure in a marine food web.
Using a marine food web model with algae, shrimp, and fish, researchers showed that combined polystyrene microplastic and cadmium exposure caused greater physiological harm than either pollutant alone, with toxicity and bioaccumulation amplified at each trophic level.
The combined effects of microplastics and the heavy metal cadmium on the marine periphytic ciliate Euplotes vannus
Researchers studied the combined toxic effects of polystyrene microplastics and the heavy metal cadmium on the marine ciliate Euplotes vannus. The study found that microplastics and cadmium together produced joint toxic effects on these single-celled organisms, which play important roles in marine food webs. Evidence indicates that microplastics may increase the bioavailability of heavy metals to marine microorganisms at the base of the food chain.
Enhanced microalgal toxicity due to polystyrene nanoplastics and cadmium co-exposure: From the perspective of physiological and metabolomic profiles
Researchers studied the combined toxicity of polystyrene nanoplastics and cadmium on the microalga Euglena gracilis and found that co-exposure produced synergistic effects, inhibiting growth by nearly 29%. The organisms activated antioxidant defenses and showed significant disruptions in carbohydrate, lipid, and amino acid metabolism. The findings suggest that nanoplastics and heavy metals together pose greater risks to aquatic microorganisms than either pollutant alone.
Toxic effects on ciliates under nano-/micro-plastics coexist with silver nanoparticles
Researchers tested the combined effects of different-sized plastic particles with silver nanoparticles on marine microorganisms and found that the mixture was more toxic than either pollutant alone. Smaller nanoplastics combined with silver nanoparticles caused the most severe damage, disrupting energy and fat metabolism and causing DNA and protein damage. This study shows how microplastics can amplify the toxicity of other environmental pollutants in marine food chains.
Microplastics at an environmentally relevant dose enhance mercury toxicity in a marine copepod under multigenerational exposure: Multi-omics perspective
Researchers exposed tiny marine organisms called copepods to microplastics and mercury together across three generations at levels found in the environment. While microplastics alone had little effect, they made mercury much more toxic by increasing how much mercury built up in the organisms' bodies. This study shows that microplastics can act as carriers that amplify the harmful effects of other environmental pollutants, with the damage worsening over generations.