3HV biosynthesis from glucose and 2-ketobutyrate. This figure shows shake-flask production of chiral 3HV by recombinant E. coli grown in LB supplemented with 20 g/L glucose and 3 g/L sodium 2-ketobutyrate. Effects of overexpressing ptb-buk and using acetate pathway knockout strain HCT 20 (with additional deletions of ackA-pta. poxB, and atoDA genes compared to HCT 10) on 3HV production are compared. All strains contained the same set of plasmids pET-PB-B, and pCDF-T-H (for (S)-3HV synthesis) or pCDF-T-P (for (R)-3HV synthesis).