The effect of pH on the acute toxicity of phenanthrene in a marine microalgae Chlorella salina
The effect of pH on the acute toxicity of phenanthrene in a marine microalgae Chlorella salina
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pH值对菲对海洋微藻小球藻急性毒性的影响
DOI：
10.1038/s41598-018-35686-9
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发表时间：
2018-12-04
影响因子：
4.6
通讯作者：
Jia, Xiaoping
中科院分区：
文献类型：
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作者：
Chen, Haigang;Zhang, Zhe;Jia, Xiaoping
菲是中国大陆架环境中含量最丰富的多环芳烃之一，也是美国环保署的优先污染物。在这项研究中，菲对海藻生长速率的影响进行了测定后96小时暴露在pH 6.0，7.0，8.0，9.0，和10.0的海水盐度35。还使用即时荧光和显微镜细胞计数比较了评估生长抑制的两种测量技术。结果表明，菲的毒性随pH的降低而显著增加（p < 0.05），当pH从9.0降低到6.0时，抑制50%生长速率所需的标称浓度EC 50从1.893下降到0.237 mg L-1，当pH从10.0降低到9.0时，其下降幅度大于55%。此外，本研究中计算的标称EC 50值与原油勘探区附近菲的某些环境浓度范围相同。基于两种测量技术，结果显示，在pH 8.0、9.0和10.0下，细胞计数和荧光测量具有显著差异（p < 0.05），并且用细胞计数测量计算的标称EC 50值显著高于荧光测量。总之，目前的研究证实，海水酸化可能会影响菲对这种微藻的毒性，这鼓励进一步研究海洋生物对海洋酸化的反应。
Phenanthrene is one of the most abundant polycyclic aromatic hydrocarbons (PAHs) found in continental shelf environment of China and is on the EPA's Priority Pollutant list. In this study, the effects of phenanthrene on marine algal growth rate were determined after 96-h exposure at pH 6.0, 7.0, 8.0, 9.0, and 10.0 in seawater of salinity 35. Two measuring techniques to assess growth inhibition were also compared using prompt fluorescence and microscopic cell count. The results showed that the toxicity of phenanthrene increased significantly (p < 0.05) with decreasing pH, with the nominal concentration required to inhibit growth rate by 50%, EC50, decreasing from 1.893 to 0.237 mg L-1 as pH decreased from 9.0 to 6.0, with a decrease higher than 55% from 10.0 to 9.0. In addition, the nominal EC50 values calculated in this study were at the same range of some environmental concentrations of phenanthrene close to areas of crude oil exploration. Based on the two measuring techniques, the results showed that cell count and fluorescence measurement were significantly different (p < 0.05), and the nominal EC50 values calculated with cell count measurement were significantly higher than fluorescence measurement at pH 8.0, 9.0 and 10.0. In conclusion, the present studies confirmed that acidification of seawater could affect the toxicity of phenanthrene to this species of microalgae, and which encouraged further studies involving responses of marine organisms to ocean acidification.