Fluorescent reference strains of bacteria by chromosomal integration of a modified green fluorescent protein gene

L. B. Pinheiro, M. D. Gibbs, G. Vesey, J. J. Smith, Peter Bergquist

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)

Abstract

Fluorescent reference strains of bacteria carrying a stable chromosomally integrated single copy of the gfp gene have been developed. A modified version of the gfp gene has been generated by mutagenesis and expressed under the control of the bacteriophage lambda promoter P-L. A cassette comprising bacteriophage Mu transposon arms flanking the modified gfp gene and regulatory regions was irreversibly integrated as an in-vitro-assembled transposition complex into the genomes of Escherichia coli and Salmonella spp. The modified green fluorescent protein (GFP) protein retained the fluorescence excitation and emission wavelengths of wild-type GFP. However, it fluoresced more brightly in E. coli and Salmonella compared to wild-type GFP, presumably due to improved protein maturation. Fluorescent E. coli and Salmonella strains carrying the gfp gene cassette were easily differentiated from their respective non-fluorescent parental strains on various growth media by visualization under UV light. The bacterial strains produced by this method remained viable and stably fluorescent when incorporated into a matrix for delivery of exact numbers of viable bacterial cells for use as quality control agents in microbiological procedures.

Original languageEnglish
Pages (from-to)1287-1295
Number of pages9
JournalApplied Microbiology and Biotechnology
Volume77
Issue number6
DOIs
Publication statusPublished - Jan 2008

Keywords

  • GRAM-NEGATIVE BACTERIA
  • LACTIC-ACID BACTERIA
  • ESCHERICHIA-COLI
  • TRANSPOSITION COMPLEXES
  • MARKER
  • GFP
  • SURVIVAL
  • MUTAGENESIS
  • EXPRESSION
  • VECTORS

Cite this