Eawag, Swiss Federal Institute of Aquatic Science and Technology, CH-8600 Duebendorf, Switzerland.
Environ Sci Technol. 2012 Jul 3;46(13):7390-7. doi: 10.1021/es300734m. Epub 2012 Jun 18.
The intracellular silver accumulation ({Ag}(in)) upon exposure to carbonate coated silver nanoparticles (AgNP, 0.5-10 μM, average diameter 29 nm) and silver nitrate (20-500 nM) was examined in the wild type and in the cell wall free mutant of the green alga Chlamydomonas reinhardtii at pH 7.5. The {Ag}(in) was measured over time up to 1 h after a wash procedure to remove silver ions (Ag(+)) and AgNP from the algal cell surface. The {Ag}(in) increased with increasing exposure time and with increasing AgNP and AgNO(3) concentrations in the exposure media, reaching steady-state concentrations between 10(-5) and 10(-3) mol L(cell)(-1). According to estimated kinetic parameters, high Ag(+) bioconcentration factors were calculated (>10(3) L L(cell)(-1)). Higher accumulation rate constants were assessed in the cell wall free mutant, indicating a protective role of the cell wall in limiting Ag(+) uptake. The bioavailability of AgNP was calculated to be low in both strains relative to Ag(+), suggesting that AgNP internalization across the cell membrane was limited.
在 pH 值为 7.5 时，研究了暴露于碳酸涂层银纳米粒子（AgNP，0.5-10 μM，平均直径 29nm）和硝酸银（20-500 nM）的野生型和无细胞壁的绿藻衣藻突变体细胞内的银积累（{Ag}(in)）。在清洗程序后，将银离子（Ag(+))和 AgNP 从藻类细胞表面去除，测量 {Ag}(in) 在 1 小时内随时间的增加。{Ag}(in) 随暴露时间的增加和暴露介质中 AgNP 和 AgNO(3)浓度的增加而增加，达到 10(-5) 和 10(-3) mol L(cell)(-1)之间的稳定态浓度。根据估计的动力学参数，计算出了高 Ag(+)生物浓缩因子（>10(3) L L(cell)(-1)）。无细胞壁突变体中的积累率常数较高，表明细胞壁在限制 Ag(+)吸收方面起保护作用。与 Ag(+)相比，AgNP 的生物利用度在两种菌株中均较低，表明 AgNP 穿过细胞膜的内化受到限制。
