Figure 1.

Activation of P_hmuO and P_hrtBA in response to extracellular heme addition. A. The C. glutamicum wild‐type strain was transformed with one of the target gene reporters pJC1_P_hmuO‐eyfp or pJC1_P_hrtBA‐eyfp. Iron‐deprived cells were subsequently cultivated in a microbioreactor system (Biolector) in CGXII minimal medium with 2% (w/v) glucose containing 4 µM hemin. The eYFP fluorescence was measured as the output of target promoter activation, and backscatter values were recorded to monitor biomass formation. The specific fluorescence (fluorescence/backscatter) was normalized according to material and methods and the reporter activity (%) was calculated with the maximum reporter output. B. C. glutamicum ΔchrS/pJC1_P_hmuO‐eyfp and ΔhrrS/pJC1_P_hrtBA‐eyfp grown as described in (A). Non‐cognate sensor kinases do not significantly affect the response profile. [Colour figure can be viewed at wileyonlinelibrary.com]