The objective is to address the issue of Carbon Catabolite Repression(CCR)in Klebsiella pneumoniae during mixed carbon source fermentation for 2,3-butanediol(2,3-BD)production,which leads to a decrease in production efficiency.In this study,a Cm resistance gene was used as a marker,and the ptsG gene deletion strain of K.pneumoniae HD79-N was successfully constructed using the λRed homologous recombination technique.Furthermore,the fermentation results using a mixed carbon source of glucose and xylose(glucose:xylose=2:1)demonstrated that the K.pneumoniae HD79-N strain,with the ptsG gene deletion,significantly alleviated CCR,enabling simultaneous utilization of glucose and xylose for 2,3-BD production with a final yield of 9.81±0.38 g/L.Moreover,the xylose utilization rate of K.pneumoniae HD79-N strain[0.23± 0.01 g/(L·h)]was also increased by 57.82％compared to that of K.pneumoniae HD79 strain[0.15±0.00 g/(L·h)].The findings of this study provide technical insights into alleviating the CCR effect caused by the ptsG gene in K.pneumoniae strains and enhancing the production of 2,3-BD.
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