Tn5 tagging of the phenol-degrading gene on the chromosome of Pseudomonas putida.

Transposon mutagenesis was performed by the method of conjugational transfer in order to identify and characterize genes encoding enzymes involved in the pathway of phenol utilization as a carbon source. Escherichia coli, which carries the Tn5-132, Was mated with Pseudomonas putida SM25 as a host. We selected a mutant that could not utilize phenol as a carbon source. Chromosomal integration of the transposon was confirmed by Southern analysis, successfully tagging the gene related to a phenol-utilizing pathway. By cell-free enzyme and genetic complementation assays, the inactivated enzyme through the mutation of the corresponding gene was identified as the catB gene, which encodes a cis,cis-muconate lactonizing enzyme.