USE OF COLICIN-E3 FOR BIOLOGICAL CONTAINMENT OF MICROORGANISMS

The genetic determinant of the lethal antibiotic colicin E3 was cloned under the control of a tightly regulated promoter in the absence of t he gene for its cognate inhibitor. Combination of this killing cassett e with a stringent regulatory element provided a substrate-dependent c onditional suicide system that was exploited for the biological contai nment of a Pseudomonas putida strain. The lethality of a single gene c opy and the distinct and universal cellular target of the antibiotic s uggest colicin E3 as an ideal candidate for combination with other let hal functions to design highly efficient containment systems for micro organisms.