title: Direct phenotypic and genotypic detection of a recombinant pseudomonad population released into lake water.
abstract: 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.
authors.affiliation: Department of Genetics and Microbiology, University of Liverpool, United Kingdom.
authors.forename: J A
authors.initials: JA
authors.lastname: Morgan
authors.forename: C
authors.initials: C
authors.lastname: Winstanley
authors.forename: R W
authors.initials: RW
authors.lastname: Pickup
authors.forename: J G
authors.initials: JG
authors.lastname: Jones
authors.forename: J R
authors.initials: JR
authors.lastname: Saunders
mesh_terms: D015153:Blotting, Western; D050557:Catechol 2,3-Dioxygenase; D002850:Chromatography, Gel; D004274:DNA, Recombinant; D049308:Dioxygenases; D004797:Enzyme-Linked Immunosorbent Assay; D005618:Fresh Water; D005798:Genes, Bacterial; D005819:Genetic Markers; D005838:Genotype; D010105:Oxygenases / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D010957:Plasmids; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D013997:Time Factors; D014871:Water Microbiology
chemical_list: D004274:DNA, Recombinant; D005819:Genetic Markers; D010105:Oxygenases; D049308:Dioxygenases; D050557:Catechol 2,3-Dioxygenase