FIGURE 10.

Gel analysis of the first PCR-screening for the markerless mutation. Forty-four colonies were screened with pair of primers FP1169/FP1170. Fifteen colonies presented only the mutant allele (M – 277 bp band), while three presented both parent and mutant alleles (X – two bands). Twenty-six colonies presented only the parent allele (P – 346 bp). Transformation efficiency was 41%. L, DNA ladder Gene Ruler 1kb plus (GenScript); DNA control, control with type strain DNA; C, colony followed by the number; M, mutant colony; P, parent strain colony; X. mixed colony presenting both parent and mutant alleles;-, DNA not detected.