探讨了短乳杆菌(Lactobacillus brevis)L2 菌株利用麦麸为培养基原料发酵生产γ-氨基丁酸(GABA),并对GABA 的分离纯化工艺进行了研究。对6 种大孔树脂和活性炭进行脱色效果筛选,ADS-7 树脂对L2 菌株发酵液具有最高的脱色率和GABA 得率; 优化了ADS-7 大孔树脂脱色条件:在pH 5.0,脱色温度25 ℃,脱色时间1 h 时,脱色效率大于95%,GABA 得率达93%。优化了阳离子交换树脂D001 分离纯化GABA 的工艺条件:在25 ℃、上样脱色发酵液pH 5.0,流速为1 BV/h 下,用去离子水和1 mol/L 氨水分步洗脱效果最好。通过收集、浓缩及结晶等工艺得到针状GABA 晶体,氢核磁共振(1H NMR)分析氢谱图与GABA 标准品一致。
Fermentative production of γ-aminobutyric acid (GABA) by Lactobacillus brevis using wheat bran as raw material and purification of GABA from fermentation broth were studied. Six kinds of macroporous resins and activated carbon were screened and the results indicated that resin ADS -7 had the highest decolorization ability and GABA yield. The optimal ADS -7 decolorization conditions were as follows: pH 5.0, decolorization temperature 25 ℃, decolorization
time 1 h. Under these conditions, the decolorizing efficiency was more than 95%, and the GABA yield reached up to 93%. The purification conditions of GABA by D001 cation exchange resin were optimized as follows: temperature 25 ℃, fermentation broth pH 5.0, flow rate 1 BV/h, elution with deionized water and 1 mol/L ammonia. Needle GABA crystal was obtained through concentration and crystallization, and confirmed by 1H NMR analysis.