Wang, Qinghui;
Gu, Jinjie;
Shu, Lin;
Jiang, Weiyan;
Mojovic, Ljiljana;
Knezevic-Jugovic, Zorica;
Shi, Jiping;
... Hao, Jian; + view all
(2022)
Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in L-valine production.
World Journal of Microbiology and Biotechnology
, 38
(5)
, Article 81. 10.1007/s11274-022-03266-9.
Preview |
Text
Baganz_WIBI-D-22-00093-Clear version.pdf Download (1MB) | Preview |
Abstract
Klebsiella pneumoniae is a 2,3-butanediol producing bacterium. Nevertheless, a design and construction of L-valine production strain was studied in this paper. The first step of 2,3-butanediol synthesis and branched-chain amino acid synthesis pathways share the same step of α-acetolactate synthesis from pyruvate. However, the two pathways are existing in parallel and do not interfere with each other in the wild-type strain. A knockout of budA blocked the 2,3-butanediol synthesis pathway and resulted in the L-valine production. The budA coded an α-acetolactate decarboxylase and catalyzed the acetoin formation from α-acetolactate. Furthermore, blocking the lactic acid synthesis by knocking out of ldhA, which is encoding a lactate dehydrogenase, improved the L-valine synthesis. 2-Ketoisovalerate is the precursor of L-valine, it is also an intermediate of the isobutanol synthesis pathway, while indole-3-pyruvate decarboxylase (ipdC) is responsible for isobutyraldehyde formation from 2-ketoisovalerate. Production of L-valine has been improved by knocking out of ipdC. On the other side, the ilvE, encoding a transaminase B, reversibly transfers one amino group from glutamate to α-ketoisovalerate. Overexpression of ilvE exhibited a distinct improvement of L-valine production. The brnQ encodes a branched-chain amino acid transporter, and L-valine production was further improved by disrupting brnQ. It is also revealed that weak acidic and aerobic conditions favor L-valine production. Based on these findings, L-valine production by metabolically engineered K. pneumonia was examined. In fed-batch fermentation, 22.4 g/L of L-valine was produced by the engineered K. pneumoniae ΔbudA-ΔldhA-ΔipdC-ΔbrnQ-ilvE after 55 h of cultivation, with a substrate conversion ratio of 0.27 mol/mol glucose.
| Type: | Article |
|---|---|
| Title: | Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in L-valine production |
| Location: | Germany |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1007/s11274-022-03266-9 |
| Publisher version: | https://doi.org/10.1007/s11274-022-03266-9 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | 2,3-Butanediol, Klebsiella pneumoniae, L-valine, brnQ, ilvE, ipdC |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Biochemical Engineering UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10148080 |
Archive Staff Only
 |
View Item |
