Li S, Gao X, Xu N, Liu L, Chen J. Enhancement of acetoin production in Candida glabrata by in silico-aided metabolic engineering.
Microb Cell Fact 2014;
13:55. [PMID:
24725668 PMCID:
PMC4021295 DOI:
10.1186/1475-2859-13-55]
[Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2013] [Accepted: 04/06/2014] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND
Acetoin is a promising chemical compound that can potentially serve as a high value-added platform for a broad range of applications. Many industrial biotechnological processes are moving towards the use of yeast as a platform. The multi-auxotrophic yeast, Candida glabrata, can accumulate a large amount of pyruvate, but produces only trace amounts of acetoin. Here, we attempted to engineer C. glabrata to redirect the carbon flux of pyruvate to increase acetoin production.
RESULTS
Based on an in silico strategy, a synthetic, composite metabolic pathway involving two distinct enzymes, acetolactate synthase (ALS) and acetolactate decarboxylase (ALDC), was constructed, leading to the accumulation of acetoin in C. glabrata. Further genetic modifications were introduced to increase the carbon flux of the heterologous pathway, increasing the production of acetoin to 2.08 g/L. Additionally, nicotinic acid was employed to regulate the intracellular NADH level, and a higher production of acetoin (3.67 g/L) was obtained at the expense of 2,3-butanediol production under conditions of a lower NADH/NAD+ ratio.
CONCLUSION
With the aid of in silico metabolic engineering and cofactor engineering, C. glabrata was designed and constructed to improve acetoin production.
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