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

A search of electric-pulse induced genes in Escherichia coli was carried out by operon fusion techniques with a hybrid bacteriophage Mu, which creates transcriptional fusions of the structural gene of beta-galactosidase to the host. Among two hundred transductants tested, nine colonies showed higher expression of more than twofold when they were treated 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 of the SOS genes, did not respond to an electric pulse treatment. A possibility of the presence of the electric-pulse stimulated genes, which were not induced by DNA damages, was suggested.