UFZ Centre for Environmental Research Leipzig Halle, Department Bioanalytical Ecotoxicology, Germany.
Chemosphere. 2010 Feb;78(7):864-70. doi: 10.1016/j.chemosphere.2009.11.046. Epub 2010 Jan 13.
Ecotoxicological assessment of chemicals and contaminated sites relies on bioassays using apical endpoints such as detection of growth inhibition using suspension cultures of green algae. For valid effect assessment observable responses should be causally linked to chemical exposure and thus confounding factors should be minimised. In this study we report that concentration response relationships for substances in current standardised protocols for unicellular algal growth assays are prone to variation from ill-defined assay conditions. The currently used growth media are not optimised to provide a stable pH regime for an exposure period of 72h, resulting in undefined speciation for charged or ionising molecules. We therefore propose a modified pH-stabilised growth medium for algal bioassays and demonstrate that this can substantially reduce variation in effect determination for reference compounds.
化学品和污染场地的生态毒理学评估依赖于使用顶极终点的生物测定，例如使用绿藻悬浮培养物检测生长抑制。为了进行有效的效果评估，可观察到的反应应该与化学暴露有因果关系，因此应尽量减少混杂因素。在这项研究中，我们报告说，目前标准化的单细胞藻类生长测定中使用的物质浓度反应关系容易受到不确定的测定条件的影响。目前使用的生长培养基不能优化为 72 小时暴露期提供稳定的 pH 值，从而导致带电荷或电离分子的形态不确定。因此，我们提出了一种改良的 pH 稳定生长培养基用于藻类生物测定，并证明这可以显著减少参考化合物的效果测定中的变异性。
