Figure 2

Gel-electrophoresis of PCR products from amplified target genes ldhL (a), sigF (b) and pdhA (c). Order of strains in all three parts of the picture: M: Thermo Scientific 1 kb DNA ladder, 1 DSM 4216^T wild-type, 2 DSM 4216^T ΔldhL, 3 ET 138 wild-type, 4 ET 138 ΔldhL, 5 ET 138 ΔldhL ΔsigF, 6 ET 138 ΔldhL ΔsigF ΔpdhA. The original gel pictures without cropping are provided in Additional files 1 (for a, b) and 2 (for c). a Amplification of the region 1,000 bp up- and downstream of the ldhL gene using primers BG 3663 and 3669. The wild-type genotype results in a product of 3,036 bp, whereas the complete deletion of the ldhL gene is confirmed by a shift of the product to 2,094 bp. b Amplification of the region 1,000 bp up- and downstream of the sigF gene using primers BG 3990 and 3991. The wild-type genotype results in a product of 3,040 bp, whereas the complete deletion of the sigF gene is confirmed by a shift of the product to 2278 bp. c Amplification of the region 1,000 bp up- and downstream of the pdhA gene using primers BG 4563 and 4564. The wild-type genotype results in a product of 3,390 bp, whereas the complete deletion of the pdhA gene is confirmed by a shift of the product to 2,280 bp.