| 초록 |
Previously, the production of N-acetylglucosamine (GlcNAc) in Saccharomyces cerevisiae was improved by deletion of the genes encoding phosphofructokinase 2 (Pfk-2) isoforms, which reduced the glycolytic flux by eliminating the pathway to produce fructose-2,6-bisphosphate, an enhancer of phosphofructokinase 1 (Pfk-1). We further examined the effect of additional reduction in glycolytic flux on N-acetylglucosamine production. Glucose uptake rate was lowered by expressing a truncated glucose-sensing regulator (MTH1-ΔT). In addition, catalytically dCas9 was introduced in order to down-regulate the expression levels of PFK-1 and pyruvate kinase-1 (PYK-1). Finally, the three strategies were introduced into S. cerevisiae strains in a combinatorial way; the strain containing all three modules resulted in the highest GlcNAc production yield. The results showed that the three modules cooperatively reduced the glycolytic flux and improved GlcNAc production up to 3.03 g/L in shake flask. |
