Previous Article | Next Article ![]()
Appl Environ Microbiol, July 1998, p. 2670-2675, Vol. 64, No. 7
Göteborg University, Department of Cell
and Molecular Biology, Microbiology, SE-405 30 Göteborg, Sweden
Received 30 January 1998/Accepted 2 May 1998
Gene transfer of the conjugative plasmid pBF1 from
Pseudomonas putida to indigenous bacteria in seawater was
investigated with a detection system for gene transfer based on the
green fluorescent protein (GFP) (C. Dahlberg et al., Mol. Biol. Evol.
15:385-390, 1998). pBF1 was tagged with the gfp gene
controlled by a lac promoter which is down regulated in the
donor cell by a chromosomal repressor (lacIq).
The plasmid donor cells (Pseudomonas putida KT2442)
subsequently do not express gfp. Transfer to recipient
strains lacking the repressor results in expression of gfp.
The transconjugant can subsequently be detected by epifluorescence
microscopy on a single-cell level. By using this method, transfer of
pBF1::gfp and expression of the gfp
gene were first shown to occur during nutrient-limiting conditions to
several defined recipient bacteria in artificial seawater. Second, we
measured transfer of pBF1 from P. putida to the marine
bacterial community directly in seawater samples, on a single-cell
level, without limiting the detection of gene transfer to the
culturable fraction of bacteria. Plasmid transfer was detected on
surfaces and in bulk seawater. Seawater bacteria with different
morphologies were shown to receive the plasmid. Gene transfer
frequencies of 2.3 × 10
0099-2240/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
In Situ Detection of High Levels of Horizontal
Plasmid Transfer in Marine Bacterial Communities
6 to 2.2 × 10
4 transconjugants per recipient were recorded after 3 days of incubation.
*
Corresponding author. Mailing address: Department of
Cell and Molecular Biology, Microbiology, Box 462, SE-405 30 Göteborg, Sweden. Phone: 46 31 773 2574. Fax: 46 31 773 2599. E-mail: Malte.Hermansson{at}gmm.gu.se.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»