Global Metabolic Engineering of Glycolytic Pathway via Multicopy Integration in Saccharomyces cerevisiae

The use of renewable feedstocks for producing biofuels and biobased chemicals by engineering metabolic pathways of yeast Saccharomyces cerevisiae has recently become an attractive option. Many researchers attempted to increase glucose consumption rate by overexpressing some glycolytic enzymes because most target biobased chemicals are derived through glycolysis. However, these attempts have met with little success. In this study, to create a S. cerevisiae strain with high glucose consumption rate, we used multicopy integration to develop a global metabolic engineering strategy. Among approximately 350 metabolically engineered strains, YPH499/dPdA3-34 exhibited the highest glucose consumption rate. This strain showed 1.3-fold higher cell growth rate and glucose consumption rate than the control strain. Real-time PCR analysis revealed that transcription levels of glycolysis-related genes such as HXK2, PFK1, PFK2, PYK2, PGI1, and PGK1 in YPH499/dPdA3-34 were increased. Our strategy is thus a promising approach to optimize global metabolic pathways in S. cerevisiae.