Tn 5 to assess soil fate of genetically marked bacteria: screening for aminoglycoside-resistance advantage and labelling specificity |
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Authors: | G Recorbet A Givaudan C Steinberg R Bally P Normand G Faurie |
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Institution: | Ecologie microbienne du sol U.R.A. CNRS 1450, UniversitéC. Bernard-Lyon 1, Villeurbanne, France |
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Abstract: | Abstract The reliability of Tn 5 as labelling tool was investigated in soil microcosm. The occurence of a selective in soil microcosm. The occurence of resistances encoded by Tn 5 nptII gene was assesed by kanamycin and neomycin amendment. The bioassay developed to monitor the persistence of the soil-added kanamycin did not detect the antibiotic activity in soil extract. A nptII -engineered Escherichia coli strain showed no enhanced survival in aminoglycoside amended soil. Tn 5-marker properties were investigated within indigenous bacteria to determine the specificity of labelling to follow the fate of recombinant DNA. Kanamycin and neomycin resistant population levels made Tn 5 aminoglycoside-resistance phenotype non-sensitive enough to select a soil dissemination of the labelled DNA. The unexpected occurrence of homologous sequences among soil organisms also prevented Tn 5 from being a specific DNA marker. By contrast, colony hybridization did not reveal homology to nptII suggesting its use as a reliable gene transfer indicator. |
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Keywords: | Kanamycin Neomycin Escherichia coli Population dynamics nptII Gene Colony-hybridization |
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