초록
<P><B>Background</B></P><P>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, <I>Candida glabrata</I>, can accumulate a large amount of pyruvate, but produces only trace amounts of acetoin. Here, we attempted to engineer <I>C. glabrata</I> to redirect the carbon flux of pyruvate to increase acetoin production.</P><P><B>Results</B></P><P>Based on an <I>in silico</I> 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 <I>C. glabrata</I>. 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<SUP>+</SUP> ratio.</P><P><B>Conclusion</B></P><P>With the aid of <I>in silico</I> metabolic engineering and cofactor engineering, <I>C. glabrata</I> was designed and constructed to improve acetoin production.</P>