Team:East Chapel Hill
Improving the Efficacy of the Fluoride Riboswitch as a Visual Detector of Fluoride Concentrations in Water
Fluoride, in appropriate quantities, has been recognized as beneficial for protecting tooth enamel from decay. However, a significant problem arises when excess amounts of fluoride infiltrate drinking water. These high concentrations result in dental fluorosis, which is characterized in children by hypomineralization of the enamel. To address this, we are using the previously characterized fluoride riboswitch. Last year we developed an operon that, when fluoride binds, activates the riboswitch resulting in the transcription of the chloramphenicol acetyltransferase gene. Thus, when fluoride is present, bacterial growth can be observed in the presence of chloramphenicol. So that the fluoride riboswitch may detect lower concentrations of fluoride, we used restriction enzymes to test several promoters. We tested two different sequences of the fluoride riboswitch, labeled FRS1 and FRS2, to examine how their predicted folding pattern would change the efficacy of the operon. We found the OXB18 promoter and FRS1 to be most successful in promoting bacterial growth