The pre-treatment of lignocellulose material toward cellulosic
bioethanol production releases microbial inhibitors that severely limit
the fermentation ability of Saccharomyces cerevisiae. This study
evaluated to what degree robust xylose capable strains may improve the
fermentability of non-detoxified sugarcane bagasse (SCB) slurries
derived from steam explosion (StEX), and further compared this to
slurries derived from ammonia fibre expansion (AFEX) pre-treatment.
Initial screening in separate hydrolyses and co-fermentation processes
using StEx-SCB hydrolysates identified S. cerevisiae TP-1 and
CelluXTM4 with higher xylose consumption (≥ 88%) and ethanol
concentrations (≥ 50 g/L). Subsequent fermentations compared StEx and
AFEX pre-treated SCB material under industrially relevant fed-batch
pre-hydrolysis simultaneous saccharification and co-fermentation (PSSCF)
conditions, which resulted in only 3 g/L differences in ethanol titres
for StEx and AFEX PSSCF fermentations. The study achieved non-detoxified
whole-slurry co-fermentation using StEx pre-treated SCB, with higher
ethanol yields than previously reported, by utilising robust
xylose-capable strains.
Xylitol production from lignocellulosic whole slurry corn cob by engineered industrial Saccharomyces cerevisiae PE-2
