Sodium-Ion-Free Fermentative Production of GABA with Levilactobacillus brevis CD0817

Abstract

Gamma-aminobutyric acid (GABA) has positive effects on many physiological processes. Lactic acid bacterial production of GABA is a future trend. This study aimed to produce a sodium-ion-free GABA fermentation process for Levilactobacillus brevis CD0817. In this fermentation, both the seed and fermentation media used L-glutamic acid instead of monosodium L-glutamate as the substrate. We optimized the key factors influencing GABA formation, adopting Erlenmeyer flask fermentation. The optimized values of the key factors of glucose, yeast extract, Tween 80, manganese ion, and fermentation temperature were 10 g/L, 35 g/L, 1.5 g/L, 0.2 mM, and 30 °C, respectively. Based on the optimized data, a sodium-ion-free GABA fermentation process was developed using a 10-L fermenter. During the fermentation, L-glutamic acid powder was continuously dissolved to supply substrate and to provide the acidic environment essential for GABA synthesis. The current bioprocess accumulated GABA at up to 331 ± 8.3 g/L after 48 h. The productivity of GABA was 6.9 g/L/h and the molar conversion rate of the substrate was 98.1%. These findings demonstrate that the proposed method is promising in the fermentative preparation of GABA by lactic acid bacteria.

Microbial-Derived γ-Aminobutyric Acid: Synthesis, Purification, Physiological Function, and Applications

“…111 Recently, Li et al utilized the SINICS method to quantify GABA-producing Levilactobacillus brevis CD0817 isolated from a healthy adult fecal sample. 112 The resulting method provided a practical, high-throughput, and cost-effective approach for the relative quantitation of GABA, contributing to further research and development in this area.…”

“…A SINICS method, primarily resulting from the contribution of ethyl acetate and ethanol, was developed by optimizing the formulation of the pH, reagent, incubation temperature, and time for the relative quantitation of GABA, which aimed to maximize the stability and sensitivity of colorimetric reaction . Recently, Li et al utilized the SINICS method to quantify GABA-producing Levilactobacillus brevis CD0817 isolated from a healthy adult fecal sample . The resulting method provided a practical, high-throughput, and cost-effective approach for the relative quantitation of GABA, contributing to further research and development in this area.…”

Fork PCR: a universal and efficient genome-walking tool

“…Genome-walking is a strategy to reveal unknown flanking segments according to known DNA sequences. The application scenarios of genome-walking include but are not limited to (i) isolating microbes ( Li et al, 2023 ; Wei et al, 2023 ), (ii) mining new functional genes ( Acevedo et al, 2013 ; Qayyum et al, 2017 ), and (iii) decoding regulatory sequences of functional genes ( Yang et al, 2019 ; Wang et al, 2022 ), etc. For example, by using genome-walking, Yamada et al (2008) characterized the glycosyl hydrolase genes from termite guts and vermiform appendixes of horses; Rajapriya et al (2021) found a rare T-DNA integration event in rice.…”