Shen Dongqian, Feng Xiaoyu, Lin Dongqiang, Yao Shanjing
Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027, China.
Sheng Wu Gong Cheng Xue Bao. 2009 Sep;25(9):1345-51.
We studied the ability of lpdA gene knockout Escherichia coli to ferment different sugars in mineral salts medium for the production of pyruvate. The sugars studied were glucose, fructose, xylose and mannose at a concentration of 10 g/L. At the same time, effect of inoculum size on lpdA fermentation with glucose was studied. The strain was able to use all sugars for biomass generation and pyruvate production. The lpdA knockout mutant converted glucose, fructose, xylose and mannose to pyruvate with yields of 0.884 g/g, 0.802 g/g, 0.817 g/g and 0.808 g/L, respectively. The pyruvate accumulation curve coupled with cell growth except for mannose as carbon source. When the inoculation size increased, the rate of glucose consumption, pyruvate accumulation and cell growth increased but lower pyruvate concentration. This study demonstrates that E. coli lpdA mutant has the potential to produce pyruvic acid from xylose and mannose.
我们研究了lpdA基因敲除的大肠杆菌在矿物盐培养基中发酵不同糖类以生产丙酮酸的能力。所研究的糖类为浓度为10 g/L的葡萄糖、果糖、木糖和甘露糖。同时，研究了接种量对lpdA基因敲除菌株利用葡萄糖发酵的影响。该菌株能够利用所有糖类生成生物质并生产丙酮酸。lpdA基因敲除突变体将葡萄糖、果糖、木糖和甘露糖转化为丙酮酸的产率分别为0.884 g/g、0.802 g/g、0.817 g/g和0.808 g/L。除了以甘露糖作为碳源外，丙酮酸积累曲线与细胞生长相关。当接种量增加时，葡萄糖消耗速率、丙酮酸积累速率和细胞生长速率增加，但丙酮酸浓度降低。本研究表明，大肠杆菌lpdA突变体具有从木糖和甘露糖生产丙酮酸的潜力。
