Induction of deoxyribonucleic acid degradation inEscherichia coli by ozone

Summary Cell survival and deoxyribonucleic acid (DNA) degradation were measured for wild-typeEscherichia coli B251 cells after exposure to different concentrations of ozone. The results show that extensive breakdown of DNA occurs after ozonation and that the extent of ozone-induced DNA degradation generally correlates with the colony-forming ability of the cells.We thank Dr M.J. d'Aoust for supplying laboratory facilities. This work was jointly sponsored by the National Research Council of Canada, the Ministère de l'Education du Québec, and funds from the Université de Montréal. One of us (C.H.) acknowledges a postgraduate scholarship from the NRC of Canada.