ABSTRACT
Pseudomonas fluorescens is a common soil bacterium which has been genetically modified to contain a gene which enables it to produce light under certain conditions.19 The genes which cause this to happen are commonly found in marine bacteria and in a number of higher organisms of which the most widely known is the firefly. The development of this particular bacterium has been extremely useful to scientists studying basic soil processes, because the ability to produce light provides a tool which allows this specific micro-organism to be detected in the presence of other organisms. Furthermore, since light can only be emitted by active, living organisms, luminescence can be used as an indicator of activity in relatively natural environments. Much of the impetus for the development of such organisms has arisen because of the commercial potential to use genetically engineered micro-organisms in the environment, both for cleaning up pollutants and for controlling plant diseases. Consequently, there is a need to understand what happens to genetically engineered bacteria once they are released. This genetically engineered soil bacterium allows the investigation of microbial survival, growth, activity and dispersal within the environment, the persistence of the recombinant DNA and the potential for its transfer to micro-flora indigenous to the soil.
