A Short-Term Toxicity Screening Test Using Photobacteria -- A Feasibility Study

This report describes a feasibility study using photobacterium Beneckea harveyi as the biologic system to test for toxicity. More specifically, the bioluminescent activity was used to assess the bacterial response to toxic chemicals. The chemicals used in this study are 2,3-dinitrotoluene, 2,4-dinitrotoluene, 2,5-dinitrotoluene, 2,6-dinitrotoluene, 3,4-dinitrotoluene 2,3,6-trinitrotoluene, 2,4,6-trinitrotoluene, p-nitrobenzonitrile and m-nitrobenzonitrile. Three dose-response studies were conducted with each of the nine chemicals and an effective concentration which causes a 50% reduction in bioluminescence (EC50) was statistically computed. The mean of the three EC50 values were compared to the LD50 of rats and mice, the 96-hour LC50 for fathead minnows (Pimephales promelas), and the 48-hour EC50 for water flea (Daphnia magna). Of these comparisons, only the LD50 of male mice showed a fairly good degree of correspondence. It is concluded that reproducible dose-response curves can be obtained from the photobacterial test system and it is recommended that further testing be conducted to increase the number of compounds tested for further comparisons with other species. (Author)