# US 2003/0203459 A1 · Method for the production of D-(-)-3-hydroxybutyric acid by recombinant esherichia coli

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- Number: US 2003/0203459 A1
- Document ID: US20030203459A1
- Status: Published application
- Kind: A1
- Application number: 10/336,844
- Filed: 2003-01-06
- Published: 2003-10-30
- Earliest claimed: 2002-01-04
- Inventors: Guoqiang Chen; Jinchun Chen; Haijun Gao
- Web page: https://patentgrep.com/patent/US20030203459A1

## CPC

- C12P 7/42: Hydroxy-carboxylic acids
- C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)}

## Abstract

This invention relates to a method for the production of D-(−)-3-hydroxybutyric acid, comprising the step of culturing a recombinant strain containing genes phbA, phbB, ptb and buk by fermentation. Preferably, the recombinant strain is a strain of E. coli. The method of the invention is simple, avoiding the technique of degrading polymer to produce D-(−)-3-hydroxybutyric acid. The present method also provides improved efficiency, lowers the complicated requirement for facilities as used in traditional chemical synthesis, simplifies the complicated technique flow, and omits the complicated chiral separation step. Therefore, the present method greatly reduces the costs associated with D-(−)-3-hydroxybutyric acid production. Also, with this invention, the problems such as environmental pollution of chemical synthesis and chiral separation are overcome.

## Claims

### Claim 1

A method for the production of D-(−)-3-hydroxybutyric acid, characterized in culturing a recombinant microbial strain that harbors genes phbA, phbB, ptb, and buk by fermentation.

### Claim 2 (depends on 1)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 1, wherein the sequences of genes phbA and phbB are selected from GenBank Accession Numbers AF029714, AF078795, U47026, X93358, J04987, L01112, and L01113; the sequence of gene ptb is selected from L04468, AB035092, and AJ278958; and the sequence of gene buk is selected from L04468, AB035092.

### Claim 3 (depends on 1)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 1, wherein the recombinant strain is E. coli.

### Claim 4 (depends on 3)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 3, wherein the E. coli strainis selected from JM109, HB101, DH5α or wild type strains.

### Claim 5 (depends on 1, 2, 3, 4)

The method for the production of D-(−)-3-hydroxybutyric acid as claimed in any one of claims 1-4, wherein the method comprises the steps of: (1) cloning genes phbA, phbB, ptb and buk into plasmids to construct new plasmids; (2) transforming the constructed plasmids into a bacterial strain to construct a recombinant strain; (3) culturing the recombinant strain to produce D-(−)-3-hydroxybutyric acid.

### Claim 6 (depends on 5)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein genes phbA, phbB, ptb and buk are cloned into one plasmid.

### Claim 7 (depends on 5)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein genes phbA, phbB, ptb and buk are cloned into more than one plasmids with random combination of the four genes.

### Claim 8 (depends on 5)

The method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein the recombinant strain is cultured under a temperature ranging from 28 to 42° C.

### Claim 9 (depends on 5)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein the recombinant strain is cultured under a pH ranging from 5.5 to 8.5.

### Claim 10 (depends on 5)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein the recombinant strain is cultured in a batch process.

### Claim 11 (depends on 5)

A method for the production of D-(−)-3-hydroxybutyric acid as claimed in claim 5, wherein the recombinant strain is cultured in a fed-batch process.