Fig. 3
Mobilization efficiencies of the kanamycin resistance gene at the aprE locus and the helper plasmids, pLS20cat and pLS20catΔoriT. YNB060 and YNB061 have oriTLS20 forward- and reverse-oriented to the kanamycin resistance gene (6.6F and R, respectively). Liquid cultures of the recipient strain YNB001 (comK::spc) and one of the donor strains: YNB065 (YNB060 with pLS20cat), YNB091 (YNB060 with pLS20catΔoriT), YNB066 (YNB061 with pLS20cat), YNB095 (YNB061 with pLS20catΔoriT), were mixed for conjugative transfer and spread on LB plates containing both chloramphenicol and spectinomycin (CS), both kanamycin and spectinomycin (KS), chloramphenicol, kanamycin, and spectinomycin (CKS), and spectinomycin alone. Colonies were counted as CFUs to calculate mobilization efficiencies [CFU of transconjugants (colonies on the CS, KS, and CKS plates)/CFU of total recipients (colonies on the spectinomycin plate) × 106 (ppm)]. Values are means with standard deviations from three independent experiments. ND not detected (< 0.01 ppm)