Comparison of vectors in L. monocytogenes. L. monocytogenes 7973 plasmids based on the shuttle vector pMK4 (△, ▲; pSB3005) or pUNK1 (□ ■; pSB3007) containing the gfp:luxABCDE operon under the control of the P
promoter (see Table 2). Cells were grown in MWB at 37°C and luminescence (closed symbols, Relative Light Units; RLU)) and growth measurements (open symbols) were taken at intervals. Reporter gene data are presented as RLU/OD600 nm to account for increasing cell number during the experiment.