Monitoring survival and gene transfer in soil microcosms of recombinant Escherichia coli designed to represent an industrial production strain

A genetically engineered microorganism (GEM) was designed to exemplify bacterial strains used for the production of biological material in industry. The recombinant DNA was located on a safety plasmid (pUC19). Survival and persistence of the GEM and its recombinant DNA (rDNA) was determined in soil microcosms by using different monitoring methods, including the polymerase-chain reaction, to amplify and detect the specific rDNA. Depending on nutritional status, both the GEM and its rDNA had disappeared within 16 (amended soil) or 28 days (non-amended soil) with a limit of detection of 5 cells/g soil and 20 fg DNA/g soil.