Engineering Acetoin and meso-2,3-Butanediol Biosynthesis in E.coli

摘要: 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 The functional reconstruction of acetoin and meso-2,3-butanediol biosynthetic pathways in E. coli have been systematically explored. Pathway construction involved the vivo screening prospective pathway isozymes yeast bacterial origin. After substantial engineering host background to increase pyruvate availability, YYC202(DE3) ldhA ilvC expressing ilvBN from aldB L. lactis (encoding acetolactate synthase decarboxylase activities, respectively) was able produce up 870 mg/L acetoin, with no co-production diacetyl observed. These strains were also found small quantities meso-2,3-butanediol, suggesting existence endogenous 2,3-butanediol dehydrogenase activity that has not before characterized. Finally, co-expression bdh1 S. cerevisiae, encoding dehydrogenase, this strain resulted production 1120 glucose a yield 0.29 g/g. While disruption native lactate biosynthesis increased precursor availability strain, NADH for reduction be most important consequence deletion.