Fig. 4

Fluorescence emission yields during oxygen-limited cultures of E. coli expressing FbFP under control of the globin promoters. The vertical solid (for OTR_max ca. 7 mmol L⁻¹ h⁻¹) and dashed (for OTR_max ca. 11 mmol L⁻¹ h⁻¹) lines indicate the beginning (left lines) and end (right lines) of the oxygen-limited phases. Fluorescence yields were calculated by dividing the FbFP fluorescence intensity signal by the scattered light intensity signal at every time-point. Empty symbols: cultures at OTRmax ca. 7 mmol L⁻¹ h⁻¹. Filled symbols: cultures at OTRmax ca. 11 mmol L⁻¹ h⁻¹. Note that the scales on the Y axes are changing. Vertical lines show the standard deviation (n = 3) of average values. a: P _Bs ; b: P _Cj ; c: P _Dr ; d: P _Sc ; e: P _St ; f: P _vgb