Fig. 6

Production of secretory SfGFP in BL21(DE3) in the presence and absence of IPTG. BL21(DE3) cells harboring a pET-based dsbA*sfgfp expression vector were cultured in LB medium at 30 °C in the absence and presence of IPTG (final concentration 0.4 mM). a To assess SfGFP production levels, we monitored 4 and 24 h after the addition of IPTG fluorescence (relative fluorescence unit, RFU) per milliliter of culture. Biomass formation was monitored by measuring the A₆₀₀. RFUs/ml per A₆₀₀ are shown in Additional file 1: Figure S1. b The localization of secretory SfGFP in BL21(DE3) cells cultured in the absence and presence of IPTG was monitored directly in whole cells using fluorescence microscopy. c The production of secretory SfGFP per cell was monitored using flow cytometry. Traces of cells cultured in the prescence of IPTG are in red and traces of cells cultured in the absence of IPTG are in black. Cells harvested after 4 h are represented by dotted lines and cells harvested after 24 h are represented by solid lines