Efficient microbial cell factory for the production of homoserine from glucose has been developed by iterative and rational engineering of Escherichia coli W3110. The whole pathway from glucose to homoserine was divided into three groups, namely, glucose transport and glycolysis (‘up-stream’), TCA and glyoxylate cycles (‘mid-stream’), and homoserine module (conversion of aspartate to homoserine and its secretion; ‘down-stream’), and the carbon flux in each group as well as between the groups were accelerated and balanced. Altogether, ∼18 genes were modified for active and consistent production of homoserine during both the actively-growing and non-growing stages of cultivation. Finally, fed-batch, two-stage bioreactor experiments, separating the growth from the production stage, were conducted for 61 h, which gave the high titer of 110.8 g/L, yield of 0.64 g/g glucose and volumetric productivity of 1.82 g/L/h, with an insignificant amount of acetate (<0.5 g/L) as the only noticeable byproduct. The metabolic engineering strategy employed in this study should be applicable for the biosynthesis of other amino acids or chemicals derived from aspartic acid.

通过大肠埃希菌的迭代合理工程，开发出高效的从葡萄糖生产高丝氨酸的微生物细胞工厂W3110。从葡萄糖到高丝氨酸的整个途径分为三组，即葡萄糖转运和糖酵解（“上游”）、TCA 和乙醛酸循环（“中游”）和高丝氨酸模块（天冬氨酸转化为高丝氨酸及其分泌;'下游'），并且每组以及组间的碳通量都得到加速和平衡。总共有 18 个基因被修饰，以在培养的积极生长和非生长阶段都积极和一致地生产高丝氨酸。最后，进行分批补料、两阶段生物反应器实验，将生长阶段与生产阶段分开，进行 61 小时，得到 110.8 g/L 的高效价，0.64 g/g 葡萄糖的产量和 1.82 g 的体积生产率/L/h，少量醋酸盐 (<0.5 g/L) 作为唯一明显的副产物。