Figure 5.

Fed-batch cultivation of R. eutropha H16 for PHB production. The culture was started with 4% (w·v⁻¹) rapeseed oil and 4.5 g·L⁻¹ urea (150 mM nitrogen). Rapeseed oil feeding linearly increased from 7 h with an initial feeding rate of 3.5 g·h⁻¹ to 35 h with a final feeding rate of 23 g·h⁻¹ up to a total concentration of 17% (w·v⁻¹). Urea (30% (w·v⁻¹)) feeding was linearly increased from 7 h with an initial feeding rate of 0.39 mL·h⁻¹ up to a final feeding rate of 6.58 mL·h⁻¹ at 16 h to a total concentration of 14.4 g·L⁻¹. In-line PHB content (upper graph, green line, wt%) by PDW spectroscopy and off-line PHB content (upper graph, green squares, wt%), estimated in-line CDW by PDW spectroscopy (bottom graph, red line, g·L⁻¹), off-line CDW (bottom graph, red filled circles, g·L⁻¹), estimated in-line RCDW by PDW spectroscopy (bottom graph, blue line, g·L⁻¹), off-line RCDW (bottom graph, blue empty circles, g·L⁻¹), and ammonia content (bottom graph, grey diamonds, mM) are shown. Error bars indicate minimum and maximum values of technical duplicates.