Use of acetate as substrate for sustainable production of homoserine and threonine by Escherichia coli W3110: A modular metabolic engineering approach.

Acetate, a promising yet underutilized carbon source for biological production, was explored for the efficient production of homoserine and threonine in Escherichia coli W. A modular metabolic engineering approach revealed the crucial roles of both acetate assimilation pathways (AckA/Pta and Acs), optimized TCA cycle flux and glyoxylate shunt activity, and enhanced CoA availability, mediated by increased pantothenate kinase activity, for efficient homoserine production. The engineered strain W-H22/pM2/pR1P exhibited a high acetate assimilation rate (5.

Metabolic engineering of Escherichia coli W3110 for efficient production of homoserine from glucose.

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.