Fig. (1) Scheme showing the location of the oligonucleotides used for the amplification of the betR gene fragments interrupted by the mini-Tn5Km transposon in the KvDSM 6 mutant, for which 2 pairs of oligonucleotides were used. The first pair allowed to amplify a region of 695 base pairs between the transposon and the end of the betR gene, while the second pair of oligonucleotides allowed to amplify a region of 490 base pairs between the transposon and a region 223 base pairs upstream of the start of the betR gene.