FIG 4.

Deletion of fruK. (A) Strategy for deletion of fruK using plasmid pMBTkv021 via two independent homologous recombination events. (B) DNA fragments separated by agarose gel electrophoresis after PCR amplification of the fruK locus from genomic DNA of wild type (WT) T. kivui and of uracil-auxotrophic isolates after selection against uracil auxotrophs in the first round of selection and (C) 5-FOA resistant isolates after the second round of selection. Putative plasmid integration, orange arrow; wild type allele, blue arrow; fruK deletion (black arrow). (D) Southern blot analysis of the fruK locus with NsiI-digested DNA from T. kivui DSM2030 (wild type, WT; expected fragment size, 2,668 bp) and the ΔfruK strain (expected fragment size, 1,735 bp).