Effect of Gene knockout of cdd and thrA on Cytidine Production in E. coli

In order to develop a host strain to produce cytidine,a synthetic pathway has been constructed for the production of cytidine from glucose in Escherichia coli.Cytidine deaminase cdd gene was deleted from an E.coli AU39 wild type strain to develop AU39(Δcdd).Then homoserine dehydrogenase gene(thrA) was deleted from an AU39(Δcdd) strain to develop AU39(ΔcddΔthrA),the intracellular concentration of aspartate was expected to be increased.Compared with the cytidine production in AU39,the cytidine production in AU39(Δcdd) and AU39(ΔcddΔthrA) were increased by 1.25 and 1.6-folds.It was concluded that a cytidine-producing strain with a relatively high yield can be developed using a metabolic engineering approach.