RECOMBINANT PLASMID MOBILIZATION BETWEEN ESCHERICHIA-COLI STRAINS IN 7 STERILE MICROCOSMS

Transfer by mobilization of a pBR derivative recombinant plasmid lacki ng transfer functions (oriT(+), tra(-), mob(-)) from one E. coli K12 s train to another was investigated in seven sterile microcosms correspo nding to different environments. These microcosms were chosen as repre sentative of environments that genetically engineered microorganisms ( GEMOs) encounter after accidental release, namely attached biomass in aquatic environments (biofilm), soil, seawater, freshwater, wastewater , mouse gut, and mussel gut. GEMOs survived in the same way as the hos t strains in all microcosms. Recombinant DNA mobilization occurred in the mouse gut, in sterile soil, and in biofilm. The plasmid transfer r ates principally reflected the environmental conditions encountered in each microcosm.