A method for producing l-valine
By introducing the LeuDHV22I gene and other gene modifications into Escherichia coli, and optimizing enzyme activity and fermentation conditions, the problems of low conversion rate and numerous by-products in L-valine production were solved, achieving efficient L-valine production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- MEIHUA BIOTECH LANGFANG CO LTD
- Filing Date
- 2024-12-13
- Publication Date
- 2026-06-16
AI Technical Summary
Existing technologies for producing L-valine suffer from problems such as low conversion rate, numerous byproducts, and long production time, especially in E. coli where efficient anaerobic growth and high-yield production have not been achieved.
By introducing the LeuDHV22I gene into Escherichia coli, enhancing the activities of ilvC, ilvD, and ilvE, and reducing byproduct production through gene modification, combined with overexpression of NADH-dependent enzymes and regulatory factors, and optimizing fermentation conditions, a highly efficient L-valine-producing strain was formed.
This improved the conversion rate and yield of L-valine, reduced the generation of byproducts, and achieved efficient L-valine production.
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Abstract
Claims
1. Modified bacteria that produce L-valine, which, compared to unmodified bacteria, contain LeuDH. V22I .
2. The modified bacteria as described in claim 1, comprising one or more LeuDH cells. V22I Gene copies, preferably two to eleven, more preferably eight.
3. The modified bacteria as described in claim 1 or 2, wherein the bacteria further comprises ilv C ilv D, and / or ilv One or more modifications that enhance E activity.
4. The modified bacteria as described in claim 3, comprising one or more ilv The C gene copies are preferably two to ten, more preferably five; containing one or more copies. ilv The D gene copies are preferably two to ten copies, more preferably four copies; and / or contain one or more copies. ilv The E gene copies are preferably two to ten, and more preferably three.
5. The modified bacteria according to any one of claims 1 to 4, further comprising an amino acid sequence mutation of acetylhydroxy acid synthase IlvBN, preferably, said mutation being selected from IlvBN. G20D IlvBN V21D and IlvBN M22F .
6. The modified bacteria according to any one of claims 1 to 5, wherein the bacteria further comprises modifications to reduce byproducts, preferably, the modifications to reduce byproduct generation are selected from... avtA, ldhA, mgsA, frd, pflB, adhE, ackA, alaA and / or alaC All knockouts, truncations, and simultaneous repair of frameshift mutations to wild type, or other truncation forms with activity reduction of more than 10%.
7. The modified bacteria according to any one of claims 1 to 6, wherein the bacteria contain a transhydrogenase. pntAB Modifications that enhance gene activity.
8. The modified bacteria as claimed in any one of claims 1 to 7, wherein the bacteria comprises nadK Modifications that enhance gene activity.
9. Use of the modified bacteria as described in any one of claims 1 to 8 in increasing L-valine production.
10. A method for producing L-valine, comprising culturing the modified bacteria as described in any one of claims 1-8 in a culture medium.