Abstract:
The invention relates to a plasmid vector which does not replicate in a target organism and contains the following constituents: a) an origin of replication for a host organism which is not identical to the target organism, b) at least one genetic marker, c) optionally a section of a sequence which enables the transfer of DNA by means of conjugation (mob sequence), d) a section of a sequence which is homologous to sequences of the target organism and enables homologous recombination in the target organism, e) a gene for a galactokinase under the control of a promoter.