Metabolic engineering of <i>Corynebacterium glutamicum</i> for L-valine production.

Hailang YU; Jia LIU; Xiaomin LI; Liming LIU

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Metabolic engineering of Corynebacterium glutamicum for L-valine production.

Author: Hailang YU ¹ ; Jia LIU ¹ ; Xiaomin LI ¹ ; Liming LIU ¹
Author Information

1. Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Publication Type:Journal Article
Keywords: Corynebacterium glutamicum; L-valine; fermentation optimization; metabolic engineering
MeSH: Corynebacterium glutamicum/genetics*; Metabolic Engineering/methods*; Valine/biosynthesis*; Fermentation; Glucose/metabolism*
From: Chinese Journal of Biotechnology 2025;41(9):3504-3520
CountryChina
Language:Chinese
Abstract: L-valine is an important essential branched-chain amino acid widely used in industries such as feed, pharmaceuticals, and food. In order to further enhance the production performance of L-valine, this study systematically engineered the metabolism of a Corynebacterium glutamicum strain, preserved in the laboratory, which is capable of producing L-valine. First, strain VH-9 was obtained by enhancing the precursor supply, synthesis pathway, and transport system of L-valine. In a 5 L fermenter, the titer, yield, and productivity of L-valine were 76.6 g/L, 0.45 g/g, and 2.39 g/(L·h), respectively. Furthermore, strain VH-18 was obtained by enhancing the uptake of substrate glucose and balancing energy supply to reduce succinate accumulation, with the titer, yield, and productivity of L-valine increased to 82.7 g/L, 0.52 g/g, and 2.58 g/(L·h), respectively. After optimization of fermentation conditions, the titer, yield, and productivity of L-valine in strain VH-18 were further improved to 88.7 g/L, 0.54 g/g, and 2.77 g/(L·h), respectively. This study has achieved the high-efficiency production of L-valine through a systems metabolic engineering strategy.