Highlights
- Inhibition of marine microalgae by polystyrene nanoparticles (100 nm) was evaluated.
- Increased pCO2 mitigated growth inhibition of algal cells caused by polystyrene nanoparticles.
- Polystyrene nanoparticles achieve inhibition effect by down-regulating key enzymes of TCA cycle.
- Increased pCO2 mitigated the toxicity of polystyrene nanoparticles by upregulating ribosomes and corresponding synthesis processes.
- Aggregation of polystyrene nanoparticles was detected in acidizing experimental medium.
Abstract
Concerns about the environmental effects of nanoplastics on marine ecosystems are increasing. Ocean acidification (OA) has also become a global environmental problem. Plastic pollution occurs concomitantly with anthropogenic climate stressors such as OA. However, the combined effects of NP and OA on marine phytoplankton are still not well understood. Therefore, we have investigated the behavior of ammonia (NH2) polystyrene nanoparticles (PS NP) in f/2 medium under 1000 μatm pCO2 and discussed the toxicity of PS NP (100 nm; 0.5 and 1.5 mg/L) on Nannochloropsis oceanica under long and short-term acidification (LA and SA; pCO2 ~ 1000 μatm). We observed PS NP suspended in pCO2 1000 μatm f/2 medium aggregated to a size greater than nanoscale (1339.00 ± 76.10 nm). In addition, we found that PS NP significantly inhibited the growth of N. oceanica at two concentrations, which also produced oxidative stress. Whereas, the growth of algal cells under the coupling of acidification and PS NP was significantly better than that of single PS NP exposure. This indicated that acidification significantly alleviated the toxic effects of PS NP on N. oceanica, and long-term acidification can even promote the growth of N. oceanica under low-density NP. To further understand the mechanism, we analyzed a comparative transcriptome. The results showed that PS NP exposure inhibited the expression of genes involved in the TCA cycle. The acidification was possibly reflected in ribosomes and corresponding processes, which alleviated the negative effects of PS NP on N. oceanica by promoting the synthesis of related enzymes and proteins. This study provided a theoretical basis for assessing the damage of NP to marine phytoplankton under OA. We propose that future studies evaluating the toxicology of NP to marine ecology should consider the changing ocean climate.
Ren Y., Jia Z., Liu Y., Liang C., Zhang X., Xu D. & Ye N., 2023. Elevated pCO2 alleviates the toxic effects of polystyrene nanoparticles on the marine microalga Nannochloropsis oceanica. Science of the Total Environment 895: 164985. doi: 10.1016/j.scitotenv.2023.164985. Article.
