Figure 8.

Isobutanol production of differentilvsingle deletion strains expressing the codon-optimized cytosolic valine pathway.S. cerevisiae strains Isoy8 (Δilv2), Isoy10 (Δilv3), Isoy12 (Δilv5) and Isoy16 (Δilv2Δilv5Δilv3) were transformed with plasmid p425-synthILV235, pregrown and used for inoculation of fresh selective SCD-val containing 40 g/L glucose to an OD_600nm of 1. Fermentation experiments were performed aerobically in shake flasks at 30°C. The effect of different gene deletions were compared concerning productivity and yield of isobutanol in S. cerevisiae strains. CEN.PK2-1C transformed with p425-synthILV235 was used as a control. Panel A: isobutanol production of S. cerevisiae strains transformed with plasmid p425-synthILV235: CEN.PK2-1C (closed circle); Isoy8 (closed square); Isoy12 (closed inverted triangle); Isoy10 (closed triangle); Isoy16 (closed diamond). Panel B: isobutanol yield of different ilv deletion strains carrying p425-synthILV235. Deleted genes are indicated below the axis and are denoted with open triangle. Plus symbols denote intact genes.