| abstract |
A method of locating insertion elements (IS elements) or transposons in coryneform bacteria, a positive selection system suitable for the above, the IS elements found in this manner and their use, is disclosed. The method involves: (1) The construction of a non-self-transferrable vector mobilizable from an E. coli mobilizer strain which vector is composed of (a) A DNA segment containing a replicon functional in E. coli, (b) A second DNA segment containing the DNA fragment coding for the mobilization function (Mob site containing the oriT), (c) A third DNA segment which recombines homologously in Gram-positive bacteria and/or contains a replicon functional in coryneform bacteria, (d) A DNA segment from Bacillus subtilis containing the sacB gene, (2) Transfer of this vector by means of conjugative transfer into the coryneform recipient strains, (3) Cultivation of the transconjugants containing the vector in an DIFFERENCE 10% sucrose-containing nutrient medium, (4) Lysis of the sucrose-resistant clones, cleaving of the plasmids with restriction endonucleases and analysis of the fragments. |