Professor Yi-Jun Wu and his team (Laboratory of Molecular Toxicology in the Institute of Zoology, Chinese Academy of Sciences) has successfully estabolished a system in which genetically engineered bacteria (GEB), expressing fusion protein of enhanced green fluorescent protein (EGFP) and organophosphorus hydrolase (OPH), can degrade organophosphorus pesticides and would die when they fulfil their work. An ABC system was constructed using a dual plasmid expression system in the GEB, which can commit suicide, degrade pesticides and have the characteristic of fluorescence. One of the double plasmids is the conditional suicide plasmid for ABC system, in which the lethal gene used was the nuclease gene of Serratia marcescens without the leader-coding sequence and was placed in duplicate within the suicide plasmid and downstream of T7 promoter. The expression of suicide gene can be induced by the presence of environmental signals arabinose. The other is a compatible plasmid carring the genes of fluorescent protein and the protein that can degrade pesticide. The detection of fluorescence, the assay of enzyme activity and the experiments of suicide efficiency all confirmed the successful constrution of the GEB possessing containment system, the ability to degrade pesticides and the characteristic of fluorescence. This kind of safety-type GEB will dramatically enhance the safety of the application of GEMs to environmental pollution control. 

The results of this work were recently published in Applied Microbiology and Biotechnology (Qin Li, Yi-Jun Wu. 2009. A fluorescent genetically engineered micro-organism that degrades organophosphates and commits suicide when required. 82(4):749-756.).