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Hybrid substrate-based pH autobuffering GABA fermentation by Levilactobacillus brevis CD0817.
- Source :
- Bioprocess & Biosystems Engineering; Dec2024, Vol. 47 Issue 12, p2101-2110, 10p
- Publication Year :
- 2024
-
Abstract
- The probiotic fermentation of the bioactive substance gamma-aminobutyric acid (GABA) is an attractive research topic. There is still room for further improvement in reported GABA fermentation methods based on a single substrate (l-glutamic acid or l-monosodium glutamate). Here, we devised a pH auto-buffering strategy to facilitate the fermentation of GABA by Levilactobacillus brevis CD0817. This strategy features a mixture of neutral monosodium l-glutamate plus acidic l-glutamic acid as the substrate. This mixture provides a mild initial pH; moreover, the newly dissolved l-glutamic acid automatically offsets the pH increase caused by substrate decarboxylation, maintaining the acidity essential for GABA fermentation. In this study, a flask trial was first performed to optimize the GABA fermentation parameters of Levilactobacillus brevis CD0817. The optimized parameters were further validated in a 10 L fermenter. The flask trial results revealed that the appropriate fermentation medium was composed of powdery l-glutamic acid (750 g/L), monosodium l-glutamate (34 g/L [0.2 mol/L]), glucose (5 g/L), yeast extract (35 g/L), MnSO<subscript>4</subscript>·H<subscript>2</subscript>O (50 mg/L [0.3 mmol/L]), and Tween 80 (1.0 g/L). The appropriate fermentation temperature was 30 °C. The fermenter trial results revealed that GABA was slowly synthesized from 0–4 h, rapidly synthesized until 32 h, and finally reached 353.1 ± 8.3 g/L at 48 h, with the pH increasing from the initial value of 4.56 to the ultimate value of 6.10. The proposed pH auto-buffering strategy may be popular for other GABA fermentations. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 16157591
- Volume :
- 47
- Issue :
- 12
- Database :
- Complementary Index
- Journal :
- Bioprocess & Biosystems Engineering
- Publication Type :
- Academic Journal
- Accession number :
- 180236349
- Full Text :
- https://doi.org/10.1007/s00449-024-03088-z