The invention discloses a single-
cell plant for efficiently synthesizing alpha-
aminobutyric acid, as well as construction and application thereof, and belongs to the technical field of microorganisms. An
escherichia coli single-
cell plant which is constructed and recombined by tandem expression of L-
threonine deaminase, L-
amino acid dehydrogenase and a
dehydrogenase gene for providing
cofactor NADH circulation is used for efficiently synthesizing the alpha-
aminobutyric acid, and the expression quantity of the L-
threonine deaminase is optimized and controlled by rbs sequence, so that the problem of conversion inhibition caused by quick accumulation of an
intermediate product ketobutyric acid is solved; meanwhile, the expression quantity of the
dehydrogenase for providing
cofactor NADH circulation is optimized and controlled by a
promoter and the rbs sequence, so that the regeneration rate of the NADH is increased and the yield is finally increased. The single-
cell plant is used for performing full-cell conversion, so that substances in and out obstacles can be reduced, the conversion rate is increased,
cofactor intracellular circulation is promoted, an
external source does not need to be added, and the cost is low. Within 20 hours, the yield of the
recombinant escherichia coli single-cell plant in a 5-
liter fermentation tank is 204 g / L, the space time yield is 10.2 g / L*h, and an actual and effect strategy is provided for industrial production.