Toxic effects of nSiO2 and mPS on diatoms Nitzschia closterium f. minutissima

Jiayin Wang; Liju Tan; Qi Li; Jiangtao Wang

doi:10.1016/j.marenvres.2023.106298

Toxic effects of nSiO₂ and mPS on diatoms Nitzschia closterium f. minutissima

Mar Environ Res. 2024 Jan:193:106298. doi: 10.1016/j.marenvres.2023.106298. Epub 2023 Dec 10.

Authors

Jiayin Wang¹, Liju Tan¹, Qi Li¹, Jiangtao Wang²

Affiliations

¹ Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China.
² Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao, 266100, China. Electronic address: jtwang@ouc.edu.cn.

PMID: 38101202
DOI: 10.1016/j.marenvres.2023.106298

Abstract

To investigate the toxic mechanism of SiO₂ nanoparticles (nSiO₂) and polystyrene microplastics (mPS) on microalgae Nitzschia closterium f. minutissima, growth inhibition tests were carried out. The growth and biological responses of the algae exposed to nSiO₂ (0.5, 1, 2, 5, 10, 30 mg L^-1) and mPS (1, 5, 10, 30 and 75 mg L^-1) were explored in f/2 media for 96 h. Both micro-/nano-particles (MNPs) inhibited the growth of N. closterium f. minutissima in a concentration- and time-dependent manner. The toxic effect of mPS on N. closterium f. minutissima is higher than that of nSiO₂, because silicon is essential for diatoms to maintain cell wall integrity, and the addition of appropriate amounts of nSiO₂ can be absorbed and used as a nutrient to promote diatom growth and protect the integrity of the siliceous shell to some extent. Both MNPs induce the production of excess oxidation and activate the cellular antioxidant defense system, leading to increased SOD and CAT activity as a means to resist oxidative damage to the cell, and eliminating excess ROS and maintaining normal cell morphology and metabolism. SEM is consistent with the results of MDA, showing that mPS with high concentrations attach to the surface of algal cells to produce heterogeneous aggregates and disrupt the cell wall and cell membrane, causing the cells to expand and rupture. This study contributes to the understanding of the size effect of MNPs on the growth of marine diatom.

Keywords: Micro-/nano-particles; Microalgae; Nitzschia closterium f. minutissima; Oxidative damage; Photosynthetic systems; Toxic mechanism.

MeSH terms

Closterium*
Diatoms*
Microplastics
Plastics
Silicon Dioxide / metabolism
Silicon Dioxide / toxicity
Water Pollutants, Chemical* / metabolism

Substances

Microplastics
Silicon Dioxide
Plastics
Water Pollutants, Chemical