cloacae SDM during growth in glucose and glucose supplemented with 40 mM sodium acetate at mid-log stage ( n = 5). *** P < 0.001 in two-tailed Student’s t-test.Ī Copy numbers of budA in E. Data shown are means ± SD ( n = 3 independent experiments). Experiments were carried out under aerobic conditions. After 4 h of culture, the concentrations of 13C ethanol and 13C acetate were assayed. 13C sodium acetate at a concentration about 10 mM was added into the culture system of E. g Yield of 13C ethanol from 13C acetate by E. e Consumption of exogenous added 13C acetate by E. cloacae SDM (Δ budABC) using glucose as carbon source. cloacae SDM (Δ adhE) using glucose as carbon source. cloacae SDM using glucose as carbon source.
AdhE, bifunctional acetaldehyde/ethanol dehydrogenase BudB, α-acetolactate synthase BudA, α-acetolactate decarboxylase BudC, 2,3-butanediol dehydrogenase AC, acetoin 2,3-BD, 2,3-butanediol. The synthesis of a non-toxic chemical such as 2,3-BD may be viewed as a unique overflow metabolism with desirable metabolic functions.Ī Reactions related to ethanol production and 2,3-BD biosynthesis in E. Finally, we realized the co-production of ethanol and acetoin from chitin, the second most abundant natural biopolymer whose catabolism involves inevitable acetate production through the coupling acetate elimination strategy. The coupling strategy involving 2,3-BD biosynthesis and ethanol production is widely distributed in bacteria and is important for toxic acetate elimination. 2,3-BD biosynthesis from glucose supplies NADH required for acetate elimination via AdhE-catalyzed ethanol production. Both bifunctional acetaldehyde/ethanol dehydrogenase AdhE-catalyzed ethanol production and acetate-induced 2,3-BD biosynthesis are indispensable for the elimination of acetate generated during overflow metabolism. We demonstrate here that acetate increases and then decreases during the growth of a bacterium Enterobacter cloacae subsp. 2,3-Butanediol (2,3-BD) synthesis in microorganisms is an ancient metabolic process with unidentified functions. Overflow metabolism-caused acetate accumulation is a major problem that restricts industrial applications of various bacteria.
0 kommentar(er)
