The efficient co-fermentation of glucose and xylose is necessary for the economically feasible bioethanol
production from lignocellulosic biomass. Even with xylose utilizing Saccharomyces cerevisiae, the efficiency
of the lignocellulosic ethanol production remains suboptimal mainly due to the low conversion
yield of xylose to ethanol. In this study, we evaluated the co-fermentation performances of SXA-R2P-E,
a recently engineered isomerase-based xylose utilizing strain, in mixed sugars and in lignocellulosic
hydrolysates. In a high-sugar fermentation with 70 g/L of glucose and 40 g/L of xylose, SXA-R2P-E produced
50 g/L of ethanol with an yield of 0.43 g ethanol/g sugars at 72 h. From dilute acid-pretreated
hydrolysates of rice straw and hardwood (oak), the strain produced 18–21 g/L of ethanol with among
the highest yield of 0.43–0.46 g ethanol/g sugars ever reported. This study shows a highly promising
potential of a xylose isomerase-expressing strain as an industrially relevant ethanol producer from lignocellulosic
hydrolysates.