The initial sugar concentrations of the rice straw hydrolysate
media were 27.7 g/L of glucose and 20.2 g/L of xylose (Table 3).
When the sugars in the rice straw hydrolysate were fermented
using the SXA-R2P-E strain, glucose was readily fermented within
6 h (Fig. 3a). The glucose consumption rate (7.55 g/L/h at 2 h;
Fig. 3a) was 82% of the control (9.25 g/L/h at 2 h; Fig. 3b), showing
slightly decreased hydrolysate fermentation. Meanwhile, 62% of
the xylose was slowly consumed in 48 h. It appears that xylose
consumption was inhibited by other compounds (1.0 g/L of acetic
acid, 0.8 g/L of phenolics and 0.2 g/L of furfural) present in the
hydrolysates; the maximum xylose consumption rate of 0.34 g/L/
h (2–24 h; Fig. 3a) was 41% of the rate of the control, which was
0.83 g/L/h (Fig. 3b).