Application of bacterial growth kinetics to in vitro toxicity assessment of substituted phenols and anilines

Bacterial growth kinetics were applied to determine toxicity of substituted phenols and anilines serving as model toxicants. The effects observed on Escherichia coli can be quantified reliably. Additional information is obtained about the onset, the duration, and the time course of the toxic action. For most compounds under study a uniform mode of toxicity was observed, but multihalogen- and/or nitrosubstituted phenols differ in toxicity pattern. Possible reasons for the change in mechanism were examined. A comparison with published quantitative data for fish toxicity of halogenated phenols indicates good agreement with toxic effects observed in E. co/i cultures. This may lead to the possibility of replacing the more costly, less stable fish test system by this simple and reliable in vitro test system.