Cerium (Ce) and cerium oxide nanoparticles (CeO₂ NP) are increasingly used in different applications. Upon their release into the aquatic environment, the exposure of aquatic organisms becomes likely. In this study, the uptake of CeO₂ NP and Ce³⁺ into the wild type and cell wall free mutant of Chlamydomonas reinhardtii was examined upon short term exposure. Separation of CeO₂ NP and Ce³⁺ not taken up or loosely bound to the cells was performed by washing algae with EDTA.

Despite a concentration and time dependent increase of cellular Ce upon exposure to CeO₂ NP with the maximal calculated Ce concentration corresponding to 1.1 CeO₂ NP per cell, an internalization of CeO₂ NP with a mean size of 140 nm in C. reinhardtii was excluded. In contrast, dissolved Ce³⁺ (1 and 10 μM) was taken up both in the wild type and cell wall free mutant of C. reinhardtii, with a linear increase of cellular Ce within 1–2 h and maximal cellular Ce of 6.04 × 10⁻⁴ mol L_cell⁻¹ (wild type) and 9.0 × 10⁻⁵ mol L_cell⁻¹ (cell wall free mutant). Based on competition with Ca²⁺ for Ce³⁺ uptake, on the comparison of the wild type and the cell wall free mutant and on inhibition of photosynthetic yield, we suggest that no efficient uptake routes for Ce³⁺ are available in C. reinhardtii and that a fraction of the cellular Ce in the wild type strongly sorbs to the algal cell wall.

铈（Ce）和氧化铈纳米颗粒（CeO ₂ NP）越来越多地用于不同的应用中。一旦将其释放到水生环境中，就有可能暴露于水生生物。在这项研究中，通过短期暴露检查了莱茵衣藻野生型和无细胞壁突变体对CeO ₂ NP和Ce ³⁺的摄取。通过用EDTA洗涤藻类来分离未吸收或未松散结合至细胞的CeO ₂ NP和Ce ³⁺。

尽管暴露于CeO ₂ NP时细胞Ce的浓度和时间随时间增加，最大计算的Ce浓度对应于每个细胞1.1 CeO ₂ NP，但排除了Reinhardtii中平均大小为140 nm的CeO ₂ NP的内在化。相反，在野生型和无莱茵衣藻的突变体中，溶解的Ce ³⁺（1和10μM）都被吸收，细胞Ce在1-2 h内线性增加，最大细胞Ce为6.04× 10 ^-4  mol L_电池^-1（野生型）和9.0×10 ^-5  mol L_电池^-1（无细胞壁突变体）。基于与Ca ²⁺竞争Ce ³⁺吸收，野生型和无细胞壁突变体的比较以及对光合产量的抑制，我们建议在莱茵衣藻中没有有效的Ce ³⁺吸收途径。而且野生型细胞中Ce的一小部分强烈吸附到藻类细胞壁上。