Bioaccumulation of Multiwall Carbon Nanotubes in Tetrahymena thermophila by Direct Feeding or Trophic Transfer.
Bioaccumulation of Multiwall Carbon Nanotubes in Tetrahymena thermophila by Direct Feeding or Trophic Transfer.
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DOI：
10.1021/acs.est.6b01916
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发表时间：
2016-08-16
影响因子：
11.4
通讯作者：
Holden PA
中科院分区：
文献类型：
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作者：
Mortimer M;Petersen EJ;Buchholz BA;Orias E;Holden PA
消费品中含有多壁碳纳米管 (MWCNT)，这些材料可能会在产品生命周期中释放到环境中，其影响不确定。在这里，我们通过细菌猎物（铜绿假单胞菌）的营养转移与从生长培养基的直接吸收，评估了原生动物嗜热四膜虫中的多壁碳纳米管生物积累。实验使用 14C 标记的多壁碳纳米管 (14C-MWCNT) 剂量为 1 mg/L 或以下进行，该剂量被证明是低毒性的，因为对测试生物体的生长没有不利影响。这项研究的一个新颖贡献是证明了通过采用加速器质谱 (AMS) 实现低浓度（亚微克/千克）量化 MWCNT 生物累积的能力。在标称浓度为 0.01 mg/L 和 1 mg/L 的 MWCNT 处理后，铜绿假单胞菌吸附了大量的 MWCNT：分别为（0.18 ± 0.04） µg/mg 和（21.9 ± 4.2） µg/mg 细菌干质量。在施用的 MWCNT 剂量为 0.3 mg/L 时，嗜热丝虫通过营养转移和直接摄取分别积累高达 (0.86 ± 0.3) µg/mg 和 (3.4 ± 1.1) µg/mg 干质量。尽管多壁碳纳米管在微生物食物链中不会生物放大，但无论喂养方式如何，多壁碳纳米管都会在原生动物种群中生物富集，这可能使多壁碳纳米管对较高营养水平的生物体具有生物利用度。
Consumer goods contain multiwall carbon nanotubes (MWCNTs) that could be released during product life cycles into the environment, where their effects are uncertain. Here, we assessed MWCNT bioaccumulation in the protozoan Tetrahymena thermophila via trophic transfer from bacterial prey (Pseudomonas aeruginosa) versus direct uptake from growth media. The experiments were conducted using 14C-labeled MWCNT (14C-MWCNT) doses at or below 1 mg/L, which proved subtoxic since there were no adverse effects on the growth of the test organisms. A novel contribution of this study was the demonstration of the ability to quantify MWCNT bioaccumulation at low (sub µg/kg) concentrations accomplished by employing accelerator mass spectrometry (AMS). After the treatments with MWCNTs at nominal concentrations of 0.01 mg/L and 1 mg/L, P. aeruginosa adsorbed considerable amounts of MWCNTs: (0.18 ± 0.04) µg/mg and (21.9 ± 4.2) µg/mg bacterial dry mass, respectively. At the administered MWCNT dose of 0.3 mg/L, T. thermophila accumulated up to (0.86 ± 0.3) µg/mg and (3.4 ± 1.1) µg/mg dry mass by trophic transfer and direct uptake, respectively. Although MWCNTs did not biomagnify in the microbial food chain, MWCNTs bioaccumulated in the protozoan populations regardless of the feeding regime, which could make MWCNTs bioavailable for organisms at higher trophic levels.