ISOLATION OF ELECTRIC PULSE-INDUCED ESCHERICHIA-COLI GENES BY OPERON FUSION TECHNIQUES

A search of electric-pulse induced genes in Escherichia coli was carri ed out by operon fusion techniques with a hybrid bacteriophage Mu, whi ch creates transcriptional fusions of the structural gene of beta-gala ctosidase to the host. Among two hundred transductants tested, nine co lonies showed higher expression of more than twofold when they were tr eated with electric pulses. An electric-pulse stimulated transductant was not stimulated by UV irradiation, which is known to induce an SOS response. Conversely, strain PQ37, which has an operon fusion in one o f the SOS genes, did not respond to an electric pulse treatment. A pos sibility of the presence of the electric-pulse stimulated genes, which were not induced by DNA damages, was suggested.