Microbial ecology, inoculant distribution, and gene flux within populations of bacteria colonizing the surface of plants: case study of a GMM field release in the United Kingdom

The rationale used to design investigations for the release and monitoring of a genetically modified microorganism (GMM) in the environment is described. Pseudomonas fluorescens SBW25 was selected from the natural microflora of the sugarbeet plant surface to generate a GMM. SBW25 was genetically modified with the insertion of two marker gene cassettes, kanr-xylE (kanamycin resistance and catechol 2,3 dioxygenase activity) and lacZY (β-galactosidase and lactose permease). The pre-release safety evaluation and greenhouse-based microcosm studies of the fate of the GMM in the phytosphere are described. The design of the release site in the UK is outlined. The survival, dispersal, and persistence of GMM after field release are described.