Department of Chemical Science and Engineering, Graduate School of Engineering, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe 657-8501, Japan.
Enzyme Microb Technol. 2012 Aug 10;51(3):171-6. doi: 10.1016/j.enzmictec.2012.05.010. Epub 2012 Jun 4.
Gamma-amino butyric acid (GABA) is a component of pharmaceuticals, functional foods, and the biodegradable plastic polyamide 4. Here, we report a simple and robust system to produce GABA from glucose using the recombinant Corynebacterium glutamicum strain GAD, which expresses GadB, a glutamate decarboxylase encoded by the gadB gene of Escherichia coli W3110. As confirmed by HPLC analysis, GABA fermentation by C. glutamicum GAD cultured at 30°C in GABA Production 1 (GP1) medium containing 50 g/L glucose without the addition of glutamate yielded 8.07 ± 1.53 g/L extracellular GABA after 96 h. Addition of 0.1mM pyridoxal 5'-phosphate (PLP) was found to enhance the production of GABA, whereas Tween 40 was unnecessary for GABA fermentation. Using the optimized GABA Production 2 (GP2) medium, which contained 50 g/L glucose and 0.1mM PLP, fermentation was performed in a flask at 30°C with 10% (v/v) seed culture of C. glutamicum GAD. GABA was produced in the culture supernatant with a yield of 12.37 ± 0.88 g/L after 72 h with a space-time yield of 0.172 g/L/h, which is the highest yield obtained to date for GABA from fermentation with glucose as a main carbon source.
γ-氨基丁酸（GABA）是药品、功能性食品和可生物降解塑料聚酰胺 4 的组成部分。在这里，我们报告了一种使用重组谷氨酸棒杆菌 GAD 从葡萄糖生产 GABA 的简单而强大的系统，该系统表达了谷氨酸脱羧酶 GadB，这是大肠杆菌 W3110 的 gadB 基因编码的。通过 HPLC 分析证实，在含有 50g/L 葡萄糖的 GABA 生产 1（GP1）培养基中，在 30°C 下培养谷氨酸棒杆菌 GAD ，不添加谷氨酸，经过 96 小时后，细胞外 GABA 的产量为 8.07±1.53g/L。添加 0.1mM 吡哆醛 5'-磷酸（PLP）被发现可以提高 GABA 的产量，而 Tween 40 对于 GABA 发酵不是必需的。使用优化的 GABA 生产 2（GP2）培养基，其中含有 50g/L 葡萄糖和 0.1mM PLP，在 30°C 下用 10%（v/v）谷氨酸棒杆菌 GAD 的种子培养液进行发酵。在培养上清液中生产 GABA，72 小时后产量为 12.37±0.88g/L，时空产率为 0.172g/L/h，这是迄今为止使用葡萄糖作为主要碳源发酵生产 GABA 的最高产量。
