Figure 4
Batch cultures of B. megaterium MS941dsrS at pH 5.2. (A) Time course of cell growth on glucose. Induction was carried out with 5 g/L xylose at OD578 = 0.3 for the production of the recombinant dextransucrase (DsrS). Samples were taken for proteomic analysis shortly before induction (I0), then 1 h (I1), 6 h (I6) and 10 h (I10) after induction. Also shown is the time course of a control batch culture of B. megaterium MS941dsrS without xylose induction. Samples were also taken for proteomic analysis according to the sampling periods used for the induced culture. (B) Production, distribution and secretion of DsrS during the xylose induced batch culture. DsrS was detected as three cell-associated forms: precursor DsrS with signal peptide still attached, mature DsrS without signal peptide and degraded DsrS in three fractions: secretion, cell-associated soluble fraction and cell-associated insoluble fraction, respectively.