원문정보
초록
영어
Wild type strains of Saccharomyce cerevisiae can not use xylose for growth and ethanol production. Therefore, three genes (XYL1, XYL2, and XYL3) from Pichia stipitis were introduced into S. cerevisiae through stable chromosomal integration. The resulting strain (YSX3)
utilized xylose for growth and ethanol production but the amounts of produced ethanol were not significant because the strain preferred oxidative metabolism of xylose. In order to increase ethanol production, we generated respiration-deficient mutants that form small colonies on glucose. However, the isolated petite colonies could not grow on xylose. Therefore, we performed chemical mutagenesis with NTG (nitrosoguanidine) to isolate mutant petite strains that are capable of growing on xylose. None of mutant petite strains were able to grow on xylose but one of the petite strains showed a better ethanol production in terms of yield and productivity as compared to the parental petite strain. These results were demonstrated that a combination of metabolic engineering and random mutagenesis was successful to generate a superior, xylose-utilizing s.cerevisiae, and uncovered distinctive physiological properties of the mutant.