A safety type genetically engineered bacterium with red fluorescence which can be used to degrade organophosphorus pesticides

Abstract

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.