TOL plasmid can prevent induction of chemotactic responses to aromatic acids

Growth conditions that elicited positive chemotaxis to benzoate and m-toluate in TOL- Pseudomonas putida cells failed to elicit taxis to these compounds in TOL+ cells. The inability of TOL+ cells to respond to these aromatic acids appears to be due to the preferential expression of TOL-encoded genes for aromatic degradation over chromosomally encoded genes. Expression of chromosomal genes for aromatic degradation is required for cells to form beta-ketoadipate, the inducer of benzoate and m-toluate taxis.