肺炎克雷伯氏菌生物合成1,3-丙二醇的副产物调控研究

Regulation of By-Product in Biosynthesis Process of 1,3-Propanediol by Klebsiella pneumoniae

以肺炎克雷伯氏菌(Klebsiella pneumoniae)ATCC 25955为原始菌株,利用代谢工程手段对K.pneumoniae生物合成1,3-丙二醇(1,3-PD)的副产物进行调控。通过敲除副产物合成途径关键酶编码基因,在分批补料发酵条件下,1,3-PD的产量达到83.8 g·L^(-1),生产强度提至2.79 g·L^(-1)·h^(-1);进一步结合乙酸吸收途径强化,有效解除了乙酸溢流现象,在分批补料发酵条件下,1,3-PD的产量达到94.9 g·L^(-1),生产强度提至3.16 g·L^(-1)·h^(-1)。研究表明,通过敲除副产物合成途径关键酶编码基因结合乙酸吸收途径强化能够促进1,3-PD的合成,减少副产物的产生,提高K.pneumoniae代谢甘油合成1,3-PD的产量和生产强度。

Using Klebsiella pneumoniae ATCC 25955 as a starting strain,we regulated the by-product in the biosynthesis process of 1,3-propanediol(1,3-PD)by K.pneumoniae through metabolic engineering.Through knocking out of the by-product pathway key enzyme coding genes,the yield and productivity of 1,3-PD reach 83.8 g·L^(-1) and 2.79 g·L^(-1)·h^(-1) under the condition of fed-batch fermentation,respectively.Further combined with the enhancement of acetic acid absorption pathway,the acetic acid overflow phenomenon is effectively relieved.Under the condition of fed-batch fermentation,the yield and productivity of 1,3-PD reach 94.9 g·L^(-1) and 3.16 g·L^(-1)·h^(-1),respectively.The research indicates that,through knocking out of the by-product pathway key enzyme coding genes and combining with the enhancement of acetic acid absorption pathway,the synthesis of 1,3-PD can be promoted,the production of by-products can be reduced,and the yield and productivity of 1,3-PD from metabolism of glycerol by K.pneumoniae can be improved.