Free access article

Issue Environ. Biosafety Res. Volume 1, Number 1, October 2002 Page(s) 9 - 18 DOI 10.1051/ebr:2002001

Environ. Biosafety Res. 1 (2002) 9-18
DOI: 10.1051/ebr:2002001

Towards safer vectors for the field release of recombinant bacteria

John Davison

Laboratoire de Biologie Cellulaire, Institut National de la Recherche Agronomique, INRA-Versailles, 78026 Versailles Cedex, France

Abstract
The prospect of the deliberate environmental release of genetically manipulated microorganisms has given rise to a great deal of polemic. Amongst the rational scientific concerns are those concerned with the fate of the released bacteria, the fate of the recombinant genes that they carry, the selective pressures acting upon them in different environmental situations and the long term effects on the environment and human health. All recombinant DNA is carried by vectors (plasmids, transposons or bacteriophage or remnants of these). Thus the way in which recombinant constructions are made may itself lead to potential biosafety concerns, irrespective of the host bacterium and the recombinant DNA fragment of primary interest. The purpose of the present review is to assess progress in improved vector design aimed at eliminating risks due to the way recombinant vectors are constructed. Improved vector constructions include the avoidance of the use, or removal, of antibiotic resistance genes, the use of defective transposons rather than plasmids in order to reduce horizontal transfer and the development of conditionally lethal suicide systems. More recently, new site-specific recombination systems have permitted transposon vectors to be manipulated following strain construction, but before environmental release, so that virtually all recombinant DNA not directly involved in the release experiment is eliminated. Such bacteria are thus pseudo-wild type in that they contain no heterologous DNA other than the genes of interest.

Key words: recombinant DNA / horizontal gene transfer / plasmid / transposon / vector / biological control / suicide genes / biodegradation / site-specific recombination / GMO.

Correspondence and reprints: John Davison Tel.: (33) 1 30 83 36 82; fax: (33) 1 30 83 37 28;
    e-mail: davisona@jouy.inra.fr

© ISBR, EDP Sciences 2002

What is OpenURL?