USE OF GREEN FLUORESCENT PROTEIN TO MONITOR SURVIVAL OF GENETICALLY-ENGINEERED BACTERIA IN AQUATIC ENVIRONMENTS

Many methods for detecting model genetically engineered microorganisms (GEMs) in experimental ecosystems rely on cultivation of introduced c ells. In this study, survival of Escherichia coli was monitored with t he green fluorescent protein (GFP) gene. This approach allowed enumera tion of GEMs by both plating and microscopy. Use of the GFP-marked GEM s revealed that E. coli persisted in stream water at higher densities as determined microscopically than as determined by CFU enumeration. T he GFP gene did not negatively impact the fitness of the host strain.