Metabolic engineering considerations for the heterologous expression of xylose-catabolic pathways in Saccharomyces cerevisiae
Fig 5
Pathway-targeted approaches to improve strains expressing the xylose isomerase pathway.
(A) The target genes to be deleted (gre3Δ, sor1Δ) and the target genes to be overexpressed by integration of a duplicated copy (xylA, XYL3, TAL1). (B) Relative changes in growth rates (g/L-h) on xylose of the engineered strains compared to the XI-XYL3 strain. (C) Comparison of fermentation profiles of the XI-XYL3, (XI)2-XYL3, and δ(XI)-XYL3 strains, and their pho13Δ mutants. All fermentations were performed in YP medium containing 40 g/L xylose under oxygen-limited conditions (80 rpm), with a low initial cell density (0.5 g DCW/L). Different letters represent significant differences across strains within fermentation parameters (Tukey’s test, p < 0.05). n. d.; Not detected.