Optimization of Luminescent Bacteria Toxicity Test and Application of Toxicity Reference Substance

In the traditional luminescent bacteria toxicity test,the test result is not stable and the use of virulent substance HgCl_2 as the toxicity reference substance engenders environmental pollution.In order to solve these problems,the experimental conditions were optimized by a series of experiments and the results indicated that the pH value of the samples should be adjusted to 5.0～9.0 and the best exposure time was 20 min.At the same time,zinc ion was selected as a toxicity reference substance to replace HgCl_2.The advantages of using Zn~(2+) as the reference substance are less environmental pollution,more stable result and lower price,etc.Furthermore,there is a quantitative relationship between the toxicity of Zn~(2+) and the toxicity of HgCl_2.The toxicity ratio of Zn~(2+) to HgCl_2 is about 1/12.5.Using Zn~(2+) as the toxicity reference substance is a convenient and feasible method to represent the toxicity of both chemicals and complex environmental samples.