Shikimate is a key intermediate in high demand for synthesizing valuable
antiviral drugs, such as the anti-
influenza drug and
oseltamivir (Tamiflu®). Microbial-based
shikimate production strategies have been developed to overcome the unstable and expensive supply of
shikimate derived from traditional plant extraction processes. Although
shikimate biosynthesis has been reported in several engineered bacterial species, the
shikimate production yield is still unsatisfactory. This study designed an Escherichia coli cell factory and optimized the fed-batch culture process to achieve a high titer of
shikimate production. Using the previously constructed dehydroshikimate (DHS)-overproducing E. coli strain, two genes (aroK and aroL) responsible for converting
shikimate to the next step were disrupted to facilitate
shikimate accumulation. The genes with negative effects on
shikimate biosynthesis, including tyrR,
ptsG, and pykA, were disrupted. In contrast, several
shikimate biosynthetic pathway genes, including aroB, aroD, aroF, aroG, and aroE, were overexpressed to maximize the
glucose uptake and intermediate flux. The shiA involved in
shikimate transport was disrupted, and the tktA involved in the accumulation of both PEP and E4P was overexpressed. The rationally designed
shikimate-overproducing E. coli strain grown in an optimized medium produced approximately 101 g/l of
shikimate in 7-l fed-batch fermentation, which is the highest level of
shikimate production reported thus far. Overall, rational cell factory design and culture process optimization for microbial-based
shikimate production will play a key role in complementing traditional plant-derived
shikimate production processes.