Optimization of acute toxicity test method using microplate for Vibrio fischeri

In order to determine the optimal conditions of acute toxicity test method using microplate for luminescent bacteria（ Vibrio fischeri），the effects of temperature，salinity，pH，detection temperature，testing system，dilution ratio，passages on the bioassay of V. fischeri were systematically studied with Luminous intensity or inhibitory effect on luminescent bacteria. The results showed that the growth curve of V. fischeri reached plateau and peak value faster at 20℃，but there was no significant difference of growth density and peak value at 15℃ and 20℃. The appropriate culture temperature of V. fischeri was 15℃-20℃；The optimal test temperature，salinity，pH value and test system were 15℃，15‰-35‰，5-10 and 1∶10，respectively. The bioassay results were significantly affected by both test temperature and test system of V. fischeri. There was no significant difference of bioassay results in different dilution ratio（ the range of initial luminescence intensity from 10 w to 600 w），but the acute toxicity test results of V. fischeri were significantly affected after 15 times of passages. The toxicity of ZnSO4·7H2O，HgCl2， SDS，phenol for V. fischeri had time responses and dose responses by the method above. It showed that the acute toxicity test method using microplate for V. fischeri was suitable for the toxicity assessment of pollutants above.