ME: Metabolic Engineering of Bacillus for Enhanced Product Yield

提出的研究目的是枯草芽孢杆菌的代谢工程，以减少酸的形成和提高产品产量。在大肠杆菌和枯草芽孢杆菌中进行的初步研究表明，添加柠檬酸盐可以促进其生长和产物形成。酸的形成也大大降低。这些改善与细胞中丙酮酸的水平有关。pyk基因的直接缺失、核磁共振实验和通量模型证实了这些结果。本研究的具体目标包括：(1)通过pyk突变体提高枯草芽孢杆菌的生长性能，(2)利用这些结果提高苏云金芽孢杆菌的毒素产量。

The objective of the proposed research is the metabolic engineering of Bacillus subtilis for reduced acid formation and enhanced product yield. Preliminary work in both E. coli and B. subtilis showed that the addition of citrate allowed enhancements in growth and product formation. Acid formation was also substantially lowered. These improvements were tied to the level of pyruvate in the cell. Direct deletion of the pyk gene, NMR experiments, and flux modeling confirmed these results. The specific objectives of this research include: (1) improving the performance of B. subtilis which shows reduced growth with the pyk mutant, and (2) utilization of these results for the improvement of toxin production in Bacillus thuringiensis.