| 초록 |
We demonstrate that rebalancing of metabolic fluxes at acetyl-CoA cansubstantially improve the titer and productivity of hexanoic acid. First, ahexanoic acid-producing E. coli strain was constructed byexpressing the genes coding β-ketothiolase (BktB) from Cupriavidusnecator and acetyl-CoA transferase (ACT) from Megasphaera sp.MH in a butyric acid producer strain. Expression of mhactcoding ACTincreased hexanoic acid production by 47% compared to that with an E.coli thioesterase, TesB. Next, metabolic flux was optimized at theacetyl-CoA branch point by fine-tuning the expression level of the gene foracetyl-CoA acetyltransferase (AtoB). Five different synthetic 5′-untranslatedregions (5′-UTRs) were designed for atoB using UTR Designer tomodulate the expression level of the gene. The flux-optimized variant produced528 mg/L hexanoic acid in 36 h, and this titer represents an 8.7-fold increasecompared to that of the non-optimized parental strain. |
