Fig 2.
Regulation of adiA by the araC ParaBAD and rhaSR PrhaBAD promoters. χ11552 (ΔaroD ParaBAD adiA) and χ11564 (ΔaroD PrhaBAD adiA) were cultured in the presence of various concentrations of arabinose or rhamnose (ranging from 10−1 to 10−5%), normalized and assayed by semiquantitative PCR for the level of adiA transcript (A), probed for the presence of AdiA by Western blotting (B), or tested for arginine decarboxylase activity via colorimetric assay (C). mRNA data are plotted as the means and standard errors of the means (SEM) from three independent experiments. Western blot and enzyme assay data are representative of three independent assays. In the colorimetric arginine decarboxylase assay, active enzyme raises the assay medium pH above 5.0, resulting in a color change from yellow-green (negative) to blue (positive).