【摘要】 旨在解决Klebsiella pneumoniae在利用混合碳源发酵生产2,3-丁二醇（2,3-butanediol，简称2,3-BD）时会产生碳分解代谢抑制(Carbon catabolite repression,CCR)效应，导致生产效率下降的问题。本研究以Cm抗性基因为标记，采用λRed同源重组技术成功构建ptsG基因缺失菌株K. pneumoniae HD79-N。此外，在利用葡萄糖与木糖混合碳源（葡萄糖:木糖=2:1）发酵的结果显示，K. pneumoniae HD79-N菌株由于敲除ptsG基因显著减弱了CCR效应，使其能够同步利用葡萄糖与木糖生产2,3-BD且最终产量达9.81±0.38 g/L。同时，K. pneumoniae HD79-N[0.23±0.01 g/(L·h)]菌株木糖利用率也比K. pneumoniae HD79[0.15±0.00 g/(L·h)]菌株提高了57.82%。本研究结果为缓解ptsG基因对K. pneumoniae菌株的CCR作用及提升2,3-BD的产量提供技术参考。更多还原

【Abstract】 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.更多还原