Metabolic engineering strategies for D-lactate over production in Escherichia coli.

D-lactate is an important chiral intermediate and a substrate for polylactic acid (PLA) production. Escherichia coli accumulate D-lactate as the primary fermentative product, and synthesis is directly controlled by the activity of lactate dehydrogenase, the efficiency of the carbon resource utilization, and the redox state. D-lactate accumulation is complicated by the flux through the competing metabolic routes and the indirect regulation of energymetabolism, aswell as by the unexpected interconnectivities of the cellular components in the remote metabolic routes. These effects have been extensively studied, and a number of metabolic engineering strategies have been applied to overproduce D-lactate with high titers, yields and productivities in E. coli that have been able to reduce the production costs and precisely control the fermentation process. This review summarizes the related strategiesandsuggestsdirections for further study; these directions provide guidelines for the development of other metabolic products using E. coli as an industrial platform. [ABSTRACT FROM AUTHOR]