초록
<P><B>Abstract</B></P><P>The introduction of an NADH/NAD<SUP>+</SUP> regeneration system can regulate the distribution between acetoin and 2,3‐butanediol. NADH regeneration can also enhance butanol production in coculture fermentation. In this work, a novel artificial consortium of <I>Paenibacillus polymyxa</I> CJX518 and recombinant <I>Escherichia coli</I> LS02T that produces riboflavin (VB<SUB>2</SUB>) was used to regulate the NADH/NAD<SUP>+</SUP> ratio and, consequently, the distribution of acetoin and 2,3‐butanediol by <I>P. polymyxa</I>. Compared with a pure culture of <I>P. polymyxa</I>, the level of acetoin was increased 76.7% in the <I>P. polymyxa</I> and recombinant <I>E. coli</I> coculture. Meanwhile, the maximum production and yield of acetoin in an artificial consortium with fed‐batch fermentation were 57.2 g/L and 0.4 g/g glucose, respectively. Additionally, the VB<SUB>2</SUB> production of recombinant <I>E. coli</I> could maintain a relatively low NADH/NAD<SUP>+</SUP> ratio by changing NADH dehydrogenase activity. It was also found that 2,3‐butanediol dehydrogenase activity was enhanced and improved acetoin production by the addition of exogenous VB<SUB>2</SUB> or by being in the artificial consortium that produces VB<SUB>2</SUB>. These results illustrate that the coculture of <I>P. polymyxa</I> and recombinant <I>E. coli</I> has enormous potential to improve acetoin production. It was also a novel strategy to regulate the NADH/NAD<SUP>+</SUP> ratio to improve the acetoin production of <I>P. polymyxa</I>.</P>