Abstract:The luminescent bacteria V.qinghaiensis Q67 was selected as test bacterium. Through testing with the standard material, RLU(Relative light unit ) was determined as the biological toxicity titer. The experiment had detected the toxicity of several kinds of toxic substances in food. Results showed that when the concentration of DMSO ranges from 0.1% to 1.0%, DMSO significantly improved the toxicity of V.qinghaiensis Q67 to toxic substance and had little influence to luminescent bacteria. The toxicity test with different concentrations of DMSO is significantly increased and the EC50(concentration for 50% of maximal effect) were reduced observably. The EC50 of copper, mercury, cadmium and zinc were enhanced from 43.28% to 58.50%. The efficiencies of DMSO to Tetracyclines antibiotic including chlortetracycline,tetracycline and oxytetracycline were enhanced from 8% to 11.6%.The toxicity of four antimicrobial pesticides including Two-anthraquinone, Bromothalonil, metalaxyl and iprodine like amine fluoride were promoted from 10.49% to 38.32% .DMSO stress method was suitable for a variety of toxic substances, and also could appeared in a short time (less than 30 min), which provided a new analytical method for the application of biological toxicity test in in the field of food.
