Utilization of genetically engineered microorganisms (GEMs) for bioremediation

The wide metabolic and physiological versatility of microorganisms can be u sed to degrade many pollutants. Bioremediation is the technological process whereby biological systems are harnessed to effect the clean-up of environ mental pollutants. Nowadays, microbial systems are employed in bioremediati on programmes, generally in the treatment of soils and waters contaminated with organic pollutants. There are instances where natural populations are not suitable for use in the remediation of polluted sites and therefore the utilization of genetically engineered microorganisms (GEMs) is being consi dered for in-situ bioremediation of contaminated ecosystems. The deliberate release of GEMs into the environment is a subject of considerable public c oncern. The potential risks associated with the release of GEMs into the en vironment has led to the construction of biological containment systems by which bacteria are killed in a controlled suicide process. Active biologica l containment systems usually consist of two different components, a killin g element designed to induce cell death and a control element which modulat es the expression of the killing function. (C) 1999 Society of Chemical Ind ustry.