Engineering bacterium and application thereof in preparation of (R)-6-cyano-5-hydroxy-3-tert-butyl carbonyl hexanoate

The invention discloses an engineering bacterium and an application thereof in preparation of (R)-6-cyano-5-hydroxy-3-tert-butyl carbonyl hexanoate. The engineering bacterium comprises host cells and target genes transferred to the host cells, wherein the target genes are halogenated alcohol dehalogenase genes of which the base sequence is shown in SEQ ID No. 3. The engineering bacterium disclosed by the invention is constructed by transferring the halogenated alcohol dehalogenase genes shown in SEQ ID No. 3 into the host cells, can be used for expressing a halogenated alcohol dehalogenase HHDH, and ensures that (S)-6-chloro-5-hydroxy-3-tert-butyl carbonyl hexanoate can be catalyzed into (R)-6-cyano-5-hydroxy-3-tert-butyl carbonyl hexanoate by virtue of the catalytic action of the halogenated alcohol dehalogenase; and the engineering bacterium is mild in reaction condition and simple and convenient to operate, and ensures that the transformation rate and purity of products can be improved.