| 摘要 |
The invention relates to a process for the detection of insertion elements (IS elements) or transposons in coryneform bacteria, to a positive selection system suitable for this purpose, to the IS elements found in this way and to the use thereof. The process comprises: 1.1. the construction of a vector which is mobilisable from an E. coli mobiliser strain, is not self-transferable and is composed of 1.1.1 a DNA segment containing a replicon which is functional in E. coli, 1.1.2 a second DNA segment containing the DNA fragment coding for the mobilisation function (Mob site containing the oriT), 1.1.3 a third DNA segment which undergoes homologous recombination in Gram-positive bacteria and/or contains a replicon which is functional in coryneform bacteria 1.1.4 a DNA segment which contains the sacB gene and is derived from Bacillus subtilis, 1.2. transfer of this vector by conjugative transfer into the coryneform recipient strains, 1.3. cultivation of the transconjugants containing the vector in a nutrient medium containing 10 % sucrose, 1.4. lysis of the sucrose-resistant clones, cleavage of the plasmids with restriction endonucleases and analysis of the fragments. |
