Photosynthetic production of 3-hydroxybutyrate from carbon dioxide

Patent metadata

Field	Value
Publication number	US-10246726-B2
Application number	US-201815938742-A
Country	US
Kind code	B2
Filing date	Mar 28, 2018
Priority date	May 14, 2012
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

Construction and expression of synthetic pathways to produce (S) or (R)-3-hydroxybutyrate (3HB) as enantiomerically-pure products by genetically engineering cyanobacterium Synechocystis sp. PCC 6803. Under optimized growth conditions, the pathway employing phaA and phaB from R. eutropha was the most effective, producing up to 533.4±5.5 mg/l (R)-3HB after 21 days photosynthetic cultivation. For the first time, the feasibility and high efficiency of producing 3HB using solar energy and CO 2 as sole energy and carbon sources by engineered cyanobacteria is demonstrated.

First claim

We claim:

1. A method of photosynthetic production of 3-hydroxybutyrate comprising culturing a Synechocystis cyanobacterium under conditions to produce said 3-hydroxybutyrate;
wherein said Synechocystis cyanobacterium is genetically engineered to overexpress the gene phaA2 and one or more of the genes phaB2, phaA, phaB, thil, hbd, and tesB and wherein the genes phaC and phaE have been inactivated or deleted; or
wherein said Synechocystis cyanobacterium is genetically engineered to overexpress the gene phaA2 and at least one of a phaA or a thil gene, at least one of a phaB or hbd gene, and a tesB gene, and wherein the genes phaC and phaE have been inactivated or deleted.

2. The method of claim 1 , wherein solar energy is the sole energy source during said culturing.

3. The method of claim 1 , wherein bicarbonate or CO2 is the sole carbon source during said culturing.

4. The method of claim 1 , wherein carbonate is the sole carbon source during said culturing.

5. The method of claim 1 , additionally comprising the step of multi-cycle production of 3-hydroxybutyrate by culture medium exchange.

6. The method of claim 1 , wherein 3-hydroxybutyrate production titers exceed 100 mg/l of Synechocystis culture.

7. The method of claim 1 , wherein 3-hydroxybutyrate production titers exceed 200 mg/l of Synechocystis culture.

8. The method of claim 1 , wherein said 3-hydroxybutyrate is secreted.

9. The method of claim 1 , wherein said cyanobacterium is Synechocystis sp. PCC 6803.

Assignees

• Univ Arizona State

Inventors

• Wang Bo
• Zhang Weiwen
• Meldrum Deirdre
• Nielsen David

Classifications

• C12N9/0006

  acting on CH-OH groups as donors (1.1) · CPC title

• C12Y301/0202

  Acyl-CoA hydrolase (3.1.2.20) · CPC title

• C12N9/16

  acting on ester bonds (3.1) · CPC title

• C12N9/1029

  transferring groups other than amino-acyl groups (2.3.1) · CPC title

• C07C59/01

  Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups · CPC title