Korea Institute of Science and Technology, Campus E 7.1, Universität des Saarlandes, Saarbrücken, Germany.
Korea Institute of Science and Technology, Campus E 7.1, Universität des Saarlandes, Saarbrücken, Germany.
Chemosphere. 2015 Nov;139:174-80. doi: 10.1016/j.chemosphere.2015.06.028. Epub 2015 Jun 25.
Microbial toxicity bioassays such as the Microtox® test are ubiquitously applied to measure the toxicity of chemicals and environmental samples. In many ways their operation is conducive to the testing of organic chemicals. They are of short duration, use glass cuvettes and take place at reduced temperatures in medium lacking sorbing components. All of these are expected to reduce sorptive and volatile losses, but particularly for hydrophobic organics the role of such losses in determining the bioassay response remains unclear. This study determined the response of the Microtox® test when using solvent spiking compared to passive dosing for introducing the model hydrophobic compounds acenaphthene, phenanthrene, fluoranthene and benzo(a)pyrene. Compared to solvent spiking, the apparent sensitivity of the Microtox® test with passive dosing was 3.4 and 12.4 times higher for acenaphthene and phenanthrene, respectively. Furthermore, fluoranthene only gave a consistent response with passive dosing. Benzo(a)pyrene did not result in a response with either spiking or passive dosing even at aqueous solubility. Such differences in the apparent sensitivity of the Microtox® test can be traced back to the precise definition of the dissolved exposure concentrations and the buffering of losses with passive dosing. This highlights the importance of exposure control even in simple and short-term microbial bioassays such as the Microtox® test.
微生物毒性生物测定，如 Microtox® 测试，被广泛应用于测量化学品和环境样品的毒性。在许多方面，它们的操作有利于有机化学品的测试。它们的持续时间短，使用玻璃比色皿，并在缺乏吸附成分的低温下进行。所有这些都有望减少吸附和挥发损失，但对于疏水性有机物来说，这些损失在确定生物测定反应中的作用仍不清楚。本研究确定了使用溶剂添加与被动给药相比时，Microtox® 测试对模型疏水性化合物苊、菲、荧蒽和苯并(a)芘的反应。与溶剂添加相比，对于苊和菲，被动给药时 Microtox® 测试的表观灵敏度分别高出 3.4 倍和 12.4 倍。此外，只有荧蒽在被动给药时才会产生一致的反应。即使在水溶解度下，苯并(a)芘也不会与添加或被动给药产生反应。Microtox® 测试的表观灵敏度的这种差异可以追溯到溶解暴露浓度的精确定义以及被动给药时损失的缓冲作用。这强调了即使在简单和短期的微生物生物测定，如 Microtox® 测试中，也要注意暴露控制的重要性。
