Carbon source-dependent inhibition of xyl operon expression of the Pseudomonas putida TOL plasmid.

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.