TY  - JOUR
AU  - Wang, Qinghui
AU  - Gu, Jinjie
AU  - Shu, Lin
AU  - Jiang, Weiyan
AU  - Mojović, Ljiljana
AU  - Knežević-Jugović, Zorica
AU  - Shi, Jiping
AU  - Baganz, Frank
AU  - Lye, Gary J.
AU  - Xiang, Wensheng
AU  - Hao, Jian
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5109
AB  - 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.
PB  - Springer Science and Business Media B.V.
T2  - World Journal of Microbiology and Biotechnology
T1  - Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in l-valine production
IS  - 5
SP  - 81
VL  - 38
DO  - 10.1007/s11274-022-03266-9
ER  - 

@article{
author = "Wang, Qinghui and Gu, Jinjie and Shu, Lin and Jiang, Weiyan and Mojović, Ljiljana and Knežević-Jugović, Zorica and Shi, Jiping and Baganz, Frank and Lye, Gary J. and Xiang, Wensheng and Hao, Jian",
year = "2022",
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.",
publisher = "Springer Science and Business Media B.V.",
journal = "World Journal of Microbiology and Biotechnology",
title = "Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in l-valine production",
number = "5",
pages = "81",
volume = "38",
doi = "10.1007/s11274-022-03266-9"
}

Wang, Q., Gu, J., Shu, L., Jiang, W., Mojović, L., Knežević-Jugović, Z., Shi, J., Baganz, F., Lye, G. J., Xiang, W.,& Hao, J.. (2022). Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in l-valine production. in World Journal of Microbiology and Biotechnology
Springer Science and Business Media B.V.., 38(5), 81.
https://doi.org/10.1007/s11274-022-03266-9

Wang Q, Gu J, Shu L, Jiang W, Mojović L, Knežević-Jugović Z, Shi J, Baganz F, Lye GJ, Xiang W, Hao J. Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in l-valine production. in World Journal of Microbiology and Biotechnology. 2022;38(5):81.
doi:10.1007/s11274-022-03266-9 .

Wang, Qinghui, Gu, Jinjie, Shu, Lin, Jiang, Weiyan, Mojović, Ljiljana, Knežević-Jugović, Zorica, Shi, Jiping, Baganz, Frank, Lye, Gary J., Xiang, Wensheng, Hao, Jian, "Blocking the 2,3-butanediol synthesis pathway of Klebsiella pneumoniae resulted in l-valine production" in World Journal of Microbiology and Biotechnology, 38, no. 5 (2022):81,
https://doi.org/10.1007/s11274-022-03266-9 . .