Fig. 3

Overexpression of comI and its effect on induced genetic competence. a Schematic illustration of the genomic region of the pMUTIN-comI integrant B. licheniformis CM2. Open reading frames are shown as arrows, the direction of which corresponds to the transcriptional orientation. Screening primers are denoted as black triangles, promoters are depicted as angled arrows and the t1t2t0-terminator is shown as a hairpin-structure. comI, encoding the putative competence inhibitor ComI_DSM13; ftsW, encoding a cell-division protein; gfp, green fluorescent protein gene; lacI, encodes the repressor protein LacI; ori ColE1, origin of replication; bla, encodes ampicillin resistance; ermC, erythromycin resistance gene. b Verification of the pMUTIN-comI insertion via PCR with the screening primers comI13f_KpnI and GFPseqr1 and gel electrophoresis. c Transformation efficiencies for B. licheniformis MW3.1 and B. licheniformis CM2 obtained by induced genetic competence using chromosomal DNA of B. licheniformis ∆spoIV (Hoffmann et al. 2010) to obtain uracil prototrophy (n = 3). Induction of P _spac was achieved by addition of IPTG to the cultivation medium to a final concentration of 100 µM. Transformation efficiencies for the wild type (MW3.1) were arbitrarily set as 100%. Data are given as mean ± SD of 3 independent experiments. ***p < 0.001