To effectively biodegrade organophosphorus
pesticides residue in environment, we constructed a
genetically engineered bacterium (GEB) which can not
only emit red fluorescence but also degrade organophosphorus
pesticides residue, and this GEB can commit suicide
when required. Two genes with different functions
were placed under the control of different promoters. One
was the dual gene expression vector pL-DsRed–pL-OPH
in which genes coding for DsRed and organophosphorus
hydrolase were independently placed downstream of two
pL promoters. These genes could be expressed freely as
long as the GEB was alive. The other was the conditional
suicide plasmid pDS containing two suicide cassettes
designed to induce bacteria to commit suicide when they
detect arabinose. The lethal gene used in the suicide
plasmid was the nuclease gene of
Serratia marcescens
without the leader-coding sequence. This was put under
the control of the T7 promoter. Applying this type of
secure GEB could potentially be a less hazardous
environmental strategy in degrading pesticides and
contamination.
