4.7. Reporter gene assays

For promoter activity assays in E. coli LMG194, cells were inoculated at an OD₆₀₀ of 0.05 and aerobically grown at 37 °C in microtiter plates within a Tecan Infinite F500 system (Tecan). OD₆₀₀ and luminescence were measured every 10 minutes for 8 h. Arabinose was added at a final concentration of 0.0001% (w/v) after the cells reached an OD₆₀₀ of 0.2. Data are reported as relative light units (RLU) in counts per second per milliliter per OD₆₀₀.

For reporter activity assays with P. luminescens, the OD₆₀₀, which initially was adjusted to 0.05, the cells were aerobically grown at 30 °C in microtiter plates with a Tecan Infinite F500 system (Tecan). The OD and fluorescence intensity of mCherry (560 nm excitation, 612 nm emission, 20 nm bandwidth) were measured after 8, 24 and 28 h of incubation. Data are reported as relative fluorescence units (RFU). Raw fluorescence data were normalized with the optical density (OD₆₀₀) of the respective culture.