Metabolic engineering of acetoin and meso-2, 3-butanediol biosynthesis in E. coli.
The functional reconstruction of acetoin and meso-2,3-butanediol (meso-2,3-BD) biosynthetic pathways in Escherichia coli have been explored systematically. Pathway construction involved the in vsivo screening of prospective pathway isozymes of yeast and bacterial origin. After substantial engineering of the host background to increase pyruvate availability, E. coli YYC202(DE3) ldhA(() ilvC( expressing ilvBN from E. coli and aldB from L. lactis (encoding acetolactate synthase and acetolactate decarboxylase activities, respectively) was able to produce up to 870 mg/L acetoin, with no coproduction of diacetyl observed. These strains were also found to produce small quantities of meso-2,3-BD, suggesting the existence of endogenous 2,3-BD dehydrogenase activity. Finally, the coexpression of bdh1 from S. cerevisiae, encoding 2,3-BD dehydrogenase, in this strain resulted in the production of up to 1120 mg/L meso-2,3-BD, with glucose a yield of 0.29 g/g. While disruption of the native lactate biosynthesis pathway increased pyruvate precursor availability to this strain, increased availability of NADH for acetoin reduction to meso-2,3-BD was found to be the most important consequence of ldhA deletion.
Nielsen
David R
DR
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Yoon
Sang-Hwal
SH
Yuan
Clara J
CJ
Prather
Kristala L J
KL
D000093:Acetoin / Q000378:metabolism*; D000693:Anaerobiosis; D002072:Butylene Glycols / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods*; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D005818:Genetic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways; D009154:Mutation; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics
D002072:Butylene Glycols; D003470:Culture Media; C026978:2,3-butylene glycol; D000093:Acetoin