Granted Patent B2

US 7,384,766 · App. 11/492,756 · Granted Jun 10, 2008

Abstract

Claims (19)

1. An isolated microorganism

which originally has a polyhydroxyalkanoic acid synthase gene in chromosome, in which at least a part of said polyhydroxyalkanoic acid synthase gene is substituted with an exogenous polyhydroxyalkanoic acid synthase gene to lose enzymatic activity of polypeptide encoded by said polyhydroxyalkanoic acid synthase gene originally in chromosome for expression of a single protein encoded by the exogenous polyhydroxyalkanoic acid synthase gene or a fusion protein with a protein encoded by the gene before substitution, and

produces a copolyester constituted of two or more monomer units selected from the group consisting of: 3-hydroxybutyric acid, 3-hydroxyhexanoic acid, 3-hydroxyheptanoic acid, 3-hydroxyoctanoic acid, 3-hydroxynonanoic acid, 3-hydroxydecanoic acid, 3-hydroxyundecanoic acid, 3-hydroxydodecanoic acid, 3-hydroxytridecanoic acid, 3-hydroxytetradecanoic acid, 3-hydroxypentadecanoic acid, and 3-hydroxyhexadecanoic acid.

2. The isolated microorganism according to claim 1

wherein the copolyester is constituted of monomer units of 3-hydroxybutyric acid and 3-hydroxyhexanoic acid.

3. The isolated microorganism according to claim 1

wherein the microorganism originally having a polyhydroxyalkanoic acid synthase gene in chromosome is Ralstonia eutropha.

4. The isolated microorganism according to claim 3 wherein Ralstonia eutropha is a Ralstonia eutropha H16 strain.

5. The isolated microorganism according to claim 1

wherein the exogenous polyhydroxyalkanoic acid synthase gene encodes an enzyme isolated from Aeromonas caviae or a mutant enzyme thereof which is the one produced by at least one amino acid substitution (a) or (b):

(a) substitution of serine for asparagine of the 149 th amino acid in polyhydroxyalkanoic acid synthase gene of Aeromonas caviae;

(b) substitution of glycine for aspartic acid of the 171 st amino acid in polyhydroxyalkanoic acid synthase gene of Aeromonas caviae.

6. The isolated microorganism according to claim 1

wherein the exogenous polyhydroxyalkanoic acid synthase gene encodes the amino acid sequence shown under SEQ ID NO:9.

7. A production method of a polyester

which comprises culturing the microorganism according to claim 1 and recovering polyester from the microorganism.

8. The isolated microorganism according to claim 1 ,

wherein the microorganism originally having a polyhydroxyalkanoic acid synthase gene in chromosome is Ralstonia eutropha H16 strain,

the exogenous polyhydroxyalkanoic acid synthase gene encodes the amino acid sequence shown under SEQ ID NO:9, and the initiation codon to the terminal codon of polyhydroxyalkanoic acid synthase gene are substituted with the initiation codon to the terminal codon of gene encoding the amino acid sequence shown under SEQ ID NO:9.

Assignments (18)