원문정보
초록
영어
Hemicellulose or cellulose-based biomass is the most abundant renewable resource in nature and composed of lignin and carbohydrate polymers containing glucose, xylose, arabinose, mannose and so on. As xylose is one of the major carbohydrates in hemicellulosic biomass, it
becomes an attractive feed stock for the production of value-added compounds. Bioethanol is designated as ethanol produced from renewable biomass and can be used as an alternative fuel for automobiles. Microbial production of bioethanol from hemicellulose has been developed using bacteria and yeasts. S. cerevisiae , a traditional alcohol fermenting yeast, is unable to use xylose as a sole carbon source because of its deficiency in xylose metabolic enzymes including
xylose specific transporter, xylose reductase and xylitol dehydrogenase. In this study, the xylose transport mechanism of recombinant S. cerevisiae was elucidated in kinetic and molecular levels. The zero trans -influx assays of glucose and xylose under high and low glucose conditions, and complementation experiments with sugar transporters were chosen for the investigation of xylose transport characteristics. In addition, the expression level of xylulokinase, the third enzyme in xylose metabolism, was modulated for the optimization of bioethanol production in recombinant S. cerevisiae .