γ-氨基丁酸产生菌的分离及发酵条件优化

摘要

γ-氨基丁酸（GABA）是哺乳动物体内的一种抑制性神经递质，具有许多重要的生理功能。利用酸菜、酸奶等食品进行乳酸菌的分离，通过纸层析法筛选得到1株产 GABA 量较高的菌株 Y-3，经16SrDNA 鉴定该菌株为短乳杆菌。单因素试验和正交试验确定的菌株 Y-3最佳发酵条件为：葡萄糖1.5%、酵母膏0.5%、胰蛋白胨1.5%、L-谷氨酸钠1.0%、丁二酸钠0.5%，初始 pH 为6.0，接种量6%，37℃静置培养48 h，GABA 产量达12 g/L 以上，比优化前产量提高了近5倍。%γ-amino butyric acid(GABA)as a putative inhibitory in the vertebrate nervous system,has many important physiological functions.Using filter paper chromatography method,a lacto-bacteria Y-3 highly yielding GABA was isolated from different foods such as pickled vegetable and yoghourt.Y-3 was identified as Lactobacillus brevis by its cultural characteristics,morphological characteristics and 16S rDNA sequence.The optimal fermentation medium composition by single factor and orthogonal test showed as follows:glucose 1.5%,yeast extract 0.5%,tryptone 1.5%,L-sodium glutamate 1.0%,sodium succinate 0.5%.The better fermentation conditions were as follows:initial pH 6.0,inoculation amount 6%, temperature 37 ℃,fermentation 48 h.Using this optimization conditions,the GABA yield was over 12 g/L,which increased nearly 5 times than that before optimization.