Natural organic compounds that contain fluorine are rare because living organisms—with a few exceptions—do not produce them. American scientists have now genetically engineered a microbial host for organofluorine metabolism, allowing it to produce a fluoridated intermediate known as a diketide. As reported in the journal Angewandte Chemie, the diketide could then be used as a monomer for the in vivo production of fluorinated bioplastics.