Fig 1.
Degradation of chloramphenicol (Cm) by the cell extract of Escherichia coli expressing estDL136. Lane 1, Cm standard; lane 2, Cm (80 μg/ml) incubated with the cell extract of E. coli DH5α carrying pUC119; lanes 3 and 4, crude extracts of E. coli DH5α carrying pUEst136 incubated without and with Cm, respectively. For Cm incubated with cell lysate, reactions were terminated by using the extraction method with butanol. Butanol extracts were concentrated and used for thin-layer chromatography analysis with a developing solvent of methanol/chloroform (1:3). Rf value represents retardation factor, which is the fraction of an analyte in the mobile phase in chromatography.