Table 4.

The characteristics of anaerobic fermentation of strains overexpressing STT4, RGI2, TFC3, MID2, and deleting IXR1.

Strains	μa	${\text{r}}_{\text{xylose}}^{\text{b}}$ (g g−1 DCW h−1)	${\text{r}}_{\text{xylose}}^{\text{b}}$ (g g−1 DCW h−1)	${\text{Y}}_{\text{ethanolc}}^{\text{c}}$ (g g−1 sugars)
BSGX001	0.170 ± 0.001	0.407 ± 0.005	0.191 ± 0.002	0.400 ± 0.002
STT4	0.185 ± 0.002*	0.557 ± 0.003*	0.191 ± 0.002*	0.396 ± 0.003
RGI2	0.208 ± 0.001*	0.528 ± 0.000*	0.182 ± 0.004*	0.400 ± 0.005
TFC3	0.165 ± 0.000*	0.581 ± 0.002*	0.253 ± 0.003*	0.400 ± 0.006
MID2	0.191 ± 0.001*	0.486 ± 0.002*	0.185 ± 0.002*	0.360 ± 0.003
Ixr1Δ	0.150 ± 0.002*	0.381 ± 0.003*	0.188 ± 0.001	0.402 ± 0.004

All the data are the mean value ± standard deviation of independent triplicate tests. Cells were cultured in bioreactors at 30°C and pH 5.5, and a stirring speed of 200 rpm. The anaerobic condition was maintained by sparking nitrogen into the bioreactors with a speed of 0.1 vvm.

^*p < 0.05.

^aThe specific growth rates (μ) were calculated from the data on the glucose consumption phase in the glucose and xylose co-fermentation.

^bThe specific consumption rates of xylose/ethanol (r_xylose/r_ethanol) were calculated from the data on the xylose consumption phase in the GX stage.

^cThe ethanol yields (Y_ethanol) of total sugars that strain consumed.