초록
<P><B>Abstract</B></P><P><B>BACKGROUND</B></P><P>2,3‐Butanediol (2,3‐BD) has a wide range of applications in chiral molecular synthesis, biofuel additives, and in food flavor additive manufacturing. Fermentation is a favorable method for 2,3‐BD production. However, it requires much time and produces several NADH related byproducts which compete with 2,3‐BD production. <I>Bacillus subtilis</I> has an excellent ability for 2,3‐BD production by biocatalysis. However, its production is limited by low intracellular NADH and the reversible property of acetoin reductase (AR/2,3‐BDH). The whole cell biocatalyst process with two different NADH regeneration systems was designed for efficient production of 2,3‐BD in <I>B. subtilis</I> 168.</P><P><B>RESULTS</B></P><P>Formate dehydrogenase and glucose dehydrogenase for NADH regeneration were successfully co‐expressed with acetoin reductase in <I>B. subtilis</I> 168. After optimization of biocatalyst bioconversion conditions, <I>B. subtilis</I> 168/pMA5‐<I>bdhA‐Hpa</I>II‐<I>fdh</I> yielded 74.5 g L<SUP>−1</SUP> of 2, 3‐BD with 9.3 g L<SUP>−1</SUP> h<SUP>−1</SUP> productivity by fed batch and 115.4 g of 2,3‐BD was achieved using same batch bacterium by three repeated batch bioconversions. On the other hand, 63.7 g L<SUP>−1</SUP> of 2, 3‐BD was produced with 7.92 g L<SUP>−1</SUP> h<SUP>−1</SUP> productivity by <I>B. subtilis</I> 168/pMA5‐<I>bdhA‐Hpa</I>II‐<I>gdh</I>. To our knowledge, the volume productivity obtained here is the highest ever reported for biocatalysis.</P><P><B>CONCLUSION</B></P><P>A higher productivity of 2,3‐BD from acetoin was achieved by whole cell biocatalysis with NADH regeneration systems in <I>B. subtilis</I> 168. This approach can be applied for NADH related bio‐based chemicals production to improve titer, yield and productivity. © 2017 Society of Chemical Industry</P>