Use of a cloned bacteriophage gene to disrupt bacteria

A plasmid, pUH51, was constructed, which contains the lysis gene E of bacteriophage phi X174, subjected to the regulatory region of the lac operon, as well as the lac repressor gene. This plasmid can readily replicate in any strain of E. coli and mediates lysis of the bacteria after induction of the cloned phi X174 gene E. Taking advantage of these properties, plasmid pUH51 was used as a tool for gentle disruption of E. coli. At cell concentrations below 5 X 10(10)/ml, the efficiency of this method, as measured by release of beta-galactosidase from the cells, exceeded the efficiency of conventional methods for cell breakage.