TOL plasmid-encoded degradation of benzyl alcohol by Pseudomonas putida is inhibited by glucose and other compounds related to the main carbohydrate metabolism in Pseudomonas species. We report here that this effect is exerted at the level of expression of the xyl catabolic operons, and two xyl promoters, Pu and Ps, were identified as the primary targets of this inhibition. xyl promoter activation was also inhibited by glucose in the heterologous Escherichia coli system, apparently not however by the classical mechanism of enteric catabolite repression.

Pseudomonas putida grows on benzylamine as a sole source of carbon/energy and nitrogen. Synthesis of an inducible benzylamine dehydrogenase (BMDH) depends on the specific RNA polymerase sigma factor σ54 and is subject to carbon source‐dependent inhibition. The presence of TOL plasmid pWW0 harboring the genetic information for the catabolism of toluene exerts strong inhibition of induction of BMDH activity.