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Direct phenotypic and genotypic detection of a recombinant pseudomonad population released into lake water

1989; American Society for Microbiology; Volume: 55; Issue: 10 Linguagem: Inglês

10.1128/aem.55.10.2537-2544.1989

1098-5336

J. Alun W. Morgan, Craig Winstanley, Roger W. Pickup, J. G. Jones, J. R. Saunders,

Wastewater Treatment and Nitrogen Removal

As a system for studying the fate of genetically engineered microorganisms in the environment, we have previously constructed recombinant plasmids encoding a xylE marker gene (C. Winstanley, J. A. W. Morgan, R. W. Pickup, J. G. Jones, and J. R. Saunders, Appl. Environ. Microbiol. 55:771-777, 1989). A series of direct membrane filter methods have been developed which facilitate the detection of bacterial cells harboring the xylE gene, its product, catechol 2,3-dioxygenase, and catechol 2,3-dioxygenase enzyme activity directly from water samples. These methods enable detection of recombinant populations at concentrations as low as 10(3) to 10(4) cells ml of lake water-1. Direct detection facilitates ecological studies of a range of bacterial strains containing the marker system in aquatic environments. The fate of a recombinant pseudomonad population in lake water was assessed by a combination of colony-forming ability, direct counts, and direct detection of the xylE gene and phenotypic expression of its product.