The role of soil bacteria in risk assessment analysis

Abstract

There are many possible applications for agronomically important genetically engineered microorganisms (GEMs) which would benefit plant production. These include treatment of legume seeds, biodegradation of xenobiotics, heavy metal recovery, pollution control, biological pesticides, improvement of pancreatic microorganisms and improvement of silage processes. However, more information is needed on how they survive, affect the environment, exchange genetic material with the soil microflora and possibly cause deleterious effects. Long-term experience in construction of recombinant microorganisms has enabled the construction of safe GEMs with stable genetic information. However, their deliberate release into open fields exposes them to a wide variety of environmental factors, but we cannot yet reliably assess their safety.1 The assessment of risk from deliberate releases requires the consideration of both whole ecosystems and soil microbial ecology.2 That includes an evaluation of the genetic risks to the soil microflora, the stability of the recombinant DNA (rDNA) and its undesirable dispersal.3 Thus it is necessary to identify key factors affecting gene transfer and dispersal4 within the indigenous soil microflora, to assess their influence on horizontal transfer of rDNA from GEMs and to correlate them with environmental factors.