FIG. 5.

Phenotypes of P. putida KT2442 inserted with the upp TOL catabolic segment. Shown is the result of patching three related P. putida KT2442 strains in minimal medium with the carbon source and the antibiotic indicated in each case and spraying them with 1% catechol after growth. Strain 1 is P. putida KT2442 without any insertion. It can grow only in the medium with citrate and remains white. Strain 2 is P. putida KT2442 inserted with the complex transposon mini-Tn5 [upp TOL]. The presence of the xylE and npt markers in the transposon (Fig. 4) causes the patch to become yellow (C23O⁺) and to grow in the presence of kanamycin (Km), as well as on toluene, as the only carbon source. Strain 3 is a derivative of strain 2 in which the xylE/npt portion of mini-Tn5 [upp TOL] has been deleted in vivo. Where indicated, toluene was provided as a saturating vapor phase.