초록
<P><B>Abstract</B></P><P><B>Aims</B></P><P>This study aimed to strengthen the reducing equivalent generation in <I>Klebsiella pneumoniae</I> for improving 1,3‐propanediol (PDO) production.</P><P><B>Methods and Results</B></P><P>Disruption of the <I>arcA</I> gene activated the transcription levels of the TCA cycle genes and thus increased the NADH/NAD<SUP>+</SUP> ratio by 54·2%, leading to the improved PDO titre and yield per cell from 16·1 g l<SUP>−1</SUP> and 4·0 g gDCW<SUP>−1</SUP> to 18·8 g l<SUP>−1</SUP> and 6·4 g gDCW<SUP>−1</SUP> respectively. Further <I>ldhA</I> gene deletion eliminated lactate accumulation and promoted the PDO titre to 19·9 g l<SUP>−1</SUP>. Finally, the glucose effect was weakened by deleting the <I>crr</I> gene to enhance the co‐utilization of glucose and glycerol, resulting in the increased PDO production to 23·8 g l<SUP>−1</SUP> with the glycerol conversion rate of 59·5%. The PDO titre in bioreactor was promoted from 61·2 to 78·1 g l<SUP>−1</SUP>.</P><P><B>Conclusions</B></P><P>Deletions of the <I>arcA</I> and the <I>crr</I> genes showed positive effects on the TCA cycle activity and the co‐utilization of glucose and glycerol, leading to the strengthened reducing equivalent generation and the improved PDO titre by 47·8% in shaker. The PDO titre in the bioreactor was enhanced to 78·1 g l<SUP>−1</SUP>.</P><P><B>Significance and Impact of the Study</B></P><P>This study provided novel information on generating reducing equivalent for the PDO biosynthesis by strengthening the TCA cycle and weakening the glucose effect in <I>K. pneumoniae</I>.</P>