CARBON SOURCE-DEPENDENT INHIBITION OF XYL OPERON EXPRESSION OF THE PSEUDOMONAS-PUTIDA TOL PLASMID

TOL plasmid-encoded degradation of benzyl alcohol by Pseudomonas putid a is inhibited by glucose and other compounds related to the main carb ohydrate metabolism in Pseudomonas species. We report here that this e ffect is exerted at the level of expression of the xyl catabolic opero ns, and two xyl promoters, Pu and Ps, were identified as the primary t argets 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.