Mechanisms affecting fluoride tolerance in the environmental bacterium Pseudomonas putida.
Fluoride is the anionic form of fluorine, the 13th most abundant element in Earth's crust, and it is toxic to many organisms above a threshold concentration. Environmental bacteria can withstand relatively high fluoride concentrations, but the only mechanism described so far is the CrcB-dependent efflux. CrcB-mediated export is the primary mechanism of F-tolerance in the model environmental bacterium Pseudomonas putida, yet spontaneous NaF-tolerant mutants arise in the absence of the CrcB transporter, showing that this is not the sole pathway of tolerance. We used whole-genome sequencing, proteomic, and transcriptomic analyses to identify mechanisms that affect fluoride tolerance in Pseudomonas putida.