Fig. 2
Characterization of the temperature-dependence of the growth rate (A, D), the functionality of the inducible SIP-system (B, E) and the temperature dependence of heterologous protein production (C, F) in KW1 and KW2. The doubling time (DT) of wild type KW1 (A) and KW2 (D) was calculated during exponential growth. Recombinant KW1 and KW2 strains containing a vector for inducible production of the red fluorescent protein mCherry were used to determine how expression depends on the dose of the inducer, the SppIP peptide, at 37 °C (B, E). The measured signals were normalized by dividing the fluorescent signal (RFU) by the OD600. The data shown refer to four hours after induction of the cultures. Note that almost no fluorescence was detected in cultures with no inducer. Also note that counting of the bacteria showed a similar relationship between the OD600 and the number of cells for KW1 and KW2 (see Materials and Methods section). Panels (C, F) show the temperature-dependency of mCherry-fluorescent signal at four hours after induction. All experiments (A-F) show the mean ± SD of two (B, E) or three (A,C,D,F) biological replicates