Abstract
To detect the volatile chlorinated organic compounds, trichloroethylene (TCE) and tetrachloroethylene (PCE), by the liquid Bacillus subtilis rec-assay method, the following improvements were conducted: 1) The interaction between the chemicals tested and the B. subtilis strains (H17 [rec+] and M45 [rec-] ) was conducted in sealed serum bottles, thereby avoiding evaporation of the chemicals tested. 2) The survival ratio, a significant indicator of lethal sensitivity for B. subtilis, was measured on the basis of viable cell count instead of turbidity.
With TCE, there was no difference between the survival ratios of H17 and M45. However, a difference was detected with PCE, and PCE showed the potential to damage DNA. Moreover, H17 and M45 were more sensitive to lower concentrations of PCE in the improved method than in the conventional method.
