초록
<P><B>Abstract</B></P><P>It is generally known that genes <I>dha</I>B and <I>dha</I>T are responsible for 1,3‐propanediol (1,3‐PD) production in the presence of glycerol in <I>Klebsiella pneumoniae</I> and these genes are organized in one operon. In the present study, a genetic means of increasing the enzyme activities of 1,3‐PD formation pathway through the over‐expression of 1,3‐PD opeorn was performed in <I>K. pneumoniae</I> S6. The recombinant strain S6‐PD showed 27‐ and 15‐fold increase in enzymatic activities of DhaB and DhaT, respectively with respect to wild‐type strain while failed to improve the 1,3‐PD yield due to the inadequacy of cofactor NADH. Therefore, in order to increase NADH availability, a NADH regeneration system was constructed by heterologous expression of NAD<SUP>+</SUP>‐dependent formate dehydrogenase gene (<I>fdh</I>1) from <I>Candida boidinii</I> and introduced into S6‐PD to investigate its effects on the glycerol utilization and 1,3‐PD formation. The results demonstrated that the increase of NADH availability could efficiently improve glycerol metabolism and promote 1,3‐PD yield.</P>