The invention provides a
valine production strain and a construction method and application thereof, a designed acetohydroxy acid synthase
mutant is that the 88th basic group of an ilvB
gene is changed from a to c, the 382nd basic group is changed from a to g, the 413th basic group is changed from c to t, the
gene sequence of a designed artificial
operon comprises a
promoter, an ilvB (A138V)
gene or ilvB (Q30K, S128G, A138V) gene of coding mutated acetohydroxy acid synthase, and an ilvN (G20D, I21D, I21D, I21D, I21D, I21D, I21D, I21D) gene. I22F) gene, a pyk gene for coding
pyruvate kinase, and a terminator; by designing a specific
acetohydroxyacid synthase mutant and related
biological materials and artificial
operon, the strain constructed by directional modification of the strain by using a pK18mobsacB
system gene editing technology based on
allele exchange has the advantages of good
genetic stability, high
fermentation yield and the like, and
valine can be stably produced.