초록
<P>The phosphoenolpyruvate-dependent glucose-specific phosphotransferase system (PTS<SUP>Glc</SUP>) is the main glucose uptake pathway in <I>Escherichia coli</I> that affects both substrate assimilation and metabolism leading to the product formation. In this study, the effect of single PTS<SUP>Glc</SUP> mutation on cell growth and substrate consumption was investigated by knocking out the genes involved in the phosphotransfer cascade of the PTS<SUP>Glc</SUP>. In addition, the distribution of the metabolites of mutants was analyzed. Each mutant was confirmed to have different adaptability in the presence of both glucose and xylose with different ratios, and a substrate mixture with high xylose content can be completely consumed in short time when the <I>ptsI</I> mutant is employed. Finally, <I>ptsH</I> deletion was for the first time applied for succinate production due to its well performance under anaerobic condition. Strain YL104H, in which <I>ptsH</I> was deleted, exhibited considerably increased succinate yield under both aerobic and anaerobic conditions. The succinate titer and overall productivity reached 511.11 mM and 1.01 g/L/h after 60 h during the whole-phase fermentation in a mineral salt medium. The present results demonstrated the glucose and xylose co-utilization efficiency and the product yield and productivity can be significantly improved if a suitable PTS<SUP>Glc</SUP> deletion mutant was selected.</P>