Assay of fosmidomycin detoxification by cell free extracts. Cell free extracts (CFE) were tested for inactivation of fosmidomycin. Fosmidomycin, at a final assay concentration of 20 or 200 μg/ml, was incubated with sterile 10 mM Tris pH8 (control), or M. smegmatis cell-free extract for 10 or 60 min. A 100 μl aliquot from each test sample was applied to a sterile paper disc and aseptically placed on media containing E. coli. The diameter of the zone of growth inhibition was measured. Error bars are the standard deviation of triplicate samples.