초록
Efficient xylose utilization is critical for the production of fuels from biomass hydrolysates. It is known that xylose catabolism is inhibited by glucose. In this study, we showed that ethanol also inhibits xylose catabolism. By introducing a xylose metabolic pathway into Saccharomyces cerevisiae and using evolutionary engineering, an engineered S. cerevisiae strain, W32N55, was obtained that can anaerobically ferment xylose to ethanol. The effect of ethanol on xylose utilization was investigated. The results showed that xylose catabolism was inhibited upon the addition of ethanol, and it resumed once ethanol was removed. Based on these results, a fermentation-pervaporation coupling process was developed. After the in situ removal of ethanol, 150g/L glucose and 31g/L xylose were consumed in 72h, providing a total of 76g/L ethanol and an overall total sugar yield of 0.42g/g. We believe that this strain will be valuable to the bio-ethanol industry.