Adaptive evolution of <i>Pseudomonas putida</i> in the presence of fluoride exposes novel functions of a benzoate transporter

that functions independently of the well-characterized CrcB efflux system. We show that inactivation of transcriptional regulator PP_3125 activates a transporter with an unexpected moonlighting role in fluoride tolerance, highlighting how bacteria can repurpose existing functions to survive environmental stress. This discovery deepens our understanding of microbial stress responses and suggests strategies to engineer robust microbial strains capable of thriving in fluoride-contaminated settings. Such strains could be valuable for bioremediation, sustainable bioprocessing, and other biotechnological applications where fluoride exposure limits microbial performance.