Figure 3

Maximum achievable product titers of isobutyric acid, 3-hydroxyisobutyric acid, and isobutanol during 2-ketoisovalerate biotransformations. Growing Ps. sp. strain VLB120 NTG mutants transformed with pCOM10-kivd were utilized. Exemplarily concentration profiles of 2-KIV, isobutanol and isobutyric acid in the NTG mutant Ps. sp. strain VLB120 C18 are highlighted in the upper left box. Cultivations were performed in M9* pH 7.0, 5 g L^-1 glucose in sealed shake flasks at 30°C. Cells were induced at early exponential phase with 0.05% (v/v) DCPK. At the same time point 25 mM 2-KIV was added. Hatched bars denote concurrent product degradation. ▼: 2-ketoisovalerate, □: isobutyric acid, ○: isobutanol. (n = 1, due to expensive substrate).