The invention relates to a
recombinant escherichia coli, a preparation method and a method for synthesizing 3,4-dihydroxybutyric acid, and belongs to the field of
biosynthesis. The
recombinant escherichia coli is obtained through knocking out
xylose isomerase gene xylA, 2-
keto acid aldolase
gene yjhH, 2-
keto acid aldolase
gene yagE and
alcohol dehydrogenase gene in
escherichia coli, overexpressing
xylose dehydrogenase gene and / or 2-
keto acid decarboxylase gene, and overexpressing
aldehyde dehydrogenases gene. By taking
xylose as a basic substrate, a compound substrate can be formed by adding glucose and / or glycerinum on the basis of the xylose, and the 3,4-dihydroxybutyric acid is biologically synthesized through the
recombinant escherichia coli; by-products are extremely less, and the formation of the by-products can be interdicted through passage
metabolism optimization. The recombinant
escherichia coli, the preparation method and the method for synthesizing the 3,4-dihydroxybutyric acid have the advantages that the preparation method is simple, the
production cycle is short, the cost is low, later continuous optimizing and transformation are realized, and the good industrial development and application prospect is realized.