Hybrid substrate-based pH autobuffering GABA fermentation by Levilactobacillus brevis CD0817.

Autor: Wang L; State Key Laboratory of Food Science and Resource, Nanchang University, Nanchang, 330047, China.; International Institute of Food Innovation Co., Ltd., Nanchang University, Nanchang, 330020, China.; Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China., Jia M; State Key Laboratory of Food Science and Resource, Nanchang University, Nanchang, 330047, China.; International Institute of Food Innovation Co., Ltd., Nanchang University, Nanchang, 330020, China.; Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China., Gao D; Biomedical Research Center, College of Life Sciences and Engineering, Northwest Minzu University, Lanzhou, 730030, China. gaodan0322@163.com., Li H; State Key Laboratory of Food Science and Resource, Nanchang University, Nanchang, 330047, China. hxli@ncu.edu.cn.; International Institute of Food Innovation Co., Ltd., Nanchang University, Nanchang, 330020, China. hxli@ncu.edu.cn.; Sino-German Joint Research Institute, Nanchang University, Nanchang, 330047, China. hxli@ncu.edu.cn.
Jazyk: angličtina
Zdroj: Bioprocess and biosystems engineering [Bioprocess Biosyst Eng] 2024 Dec; Vol. 47 (12), pp. 2101-2110. Date of Electronic Publication: 2024 Sep 13.
DOI: 10.1007/s00449-024-03088-z
Abstrakt: 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 4 ·H 2 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.
(© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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