The invention relates to a
genetically engineered bacterium for high producing beta-
alanine, co-culture preparation of D-
pantothenic acid, a construction method of the
genetically engineered bacterium and application of the
genetically engineered bacterium to co-culture preparation of the D-
pantothenic acid. According to the invention, original promoters of panD, aspC and ppc genes on a
genome are replaced with a pTrc99A-derived Trc
promoter and a ribosomebinding site (RBS) sequence so as to enhance synthesis of the beta-
alanine, and genes pykA and pykF are knocked out to block consumption of phosphoenolpyruvate (PEP) and modify a
glucose uptake path of
escherichia coli, and thus, a non-
phosphotransferase system (non-PTS)
transport system is enhanced to block a PTS
transport system, and synthesized precursor PEP is accumulated; on the basis,
heterologous aspartate decarboxylase genes panD and aspC of E.coli W3110 are introduced to enhance the
enzyme activity of key enzymes, so that supply and conversion of beta-
alanine precursors are enhanced; gdhA genes of E.coli W3110 are introduced to enhance cyclic regeneration of coenzymes NADP / DNAPH, and finally, the
titer of the beta-alanine is increased from 0 to 2.48g / L. The strain and a previous D-
pantothenic acid producing strain DPA 21 / pBCST3 undergo construction of a primary co-culture
system; the
inoculation ratio is optimized; and when the
inoculation ratio of the two strains is 1: 1, the co-culture strain can produce 3.08 g / L of D-pantothenic acid in a same
fermentation medium.