Figure 4

Fermentation profiles of an extended fed-batch fermentation on wheat straw hydrolysate (71 g/L glucose, 40 g/L xylose) and corresponding RI data. Fermentation conditions: reaction volume 0.25 L–5 L (4.75 L feed), working volume of 1 L, initial yeast pitch 0.5 gDW, 3 g/L urea, pH set point 5.5, 32 °C. As the working volume of 1 L is reached at 15 hours in the main fermentor the overflow is directed to the holding tanks.