Background: Succinic acid is an important platform and/or commodity or specialty chemical
with a broad range of applications. The metabolic role of pyruvate formate lyase A (pflA) in relation
to succinate production in Escherichia coli under anaerobic conditions from glycerol substrate remained
Methods: Herein, we identified pflA gene for the first time, as a novel gene knockout target for increasing
succinate production in E. coli. Guided by E. coli reconstruction iJO1366, we engineered the E. coli
host metabolism by deleting the pflA, thereby causing the up-regulation of glyceraldehyde-3-phosphate
dehydrogenase (GAPDH), which hypothetically increases the generation of NADH and the pool of
phosphoenolpyruvate (PEP) in the central carbon metabolism, required for succinate production. This
strategy produced succinic acid that is 32 fold (1.53 g l-1 in 7 days) from glycerol substrate.
Results and Conclusion: This work elucidates that pflA is a novel gene deletion target for increasing
succinic acid production from glycerol in E. coli under anaerobic conditions. In addition, these results
highlight the power of metabolic model in identifying novel gene deletion target and ultimately driving
novel biological discovery.