乳酸菌发酵法富集辣木叶中γ-氨基丁酸的研究

Enrichment of γ-Aminobutyric Acid in Moringa oleifera Leaves by Lactobacillus Fermentation

【目的】利用乳酸菌为发酵菌株,对辣木叶中的γ-氨基丁酸(γ-aminobutyric acid,GABA)进行发酵富集。【方法】对2株报道产GABA的商业菌株及两株实验室筛选产GABA的菌株进行筛选,得到最适发酵菌株。对辣木粉添加量、谷氨酸钠(MSG)添加量、初始pH、发酵温度、发酵时间进行单因素实验,并选择MSG添加量、初始pH、发酵温度,发酵时间进行正交实验,得出最佳发酵条件。【结果】4种乳酸菌产GABA能力大小依次为植物乳杆菌LK-1>植物乳杆菌S35>耐久肠球菌>干酪乳杆菌LK-1,利用植物乳杆菌LK-1发酵辣木叶,GABA的含量可高达152 mg/L。经单因素及正交实验,确定GABA的最佳发酵条件为辣木叶粉添加量为质量分数4%,MSG添加量为4g/L,初始pH6.5,发酵温度为35℃,发酵时间72h。在此条件下发酵辣木液GABA质量浓度可高达209mg/L,比未发酵的辣木液提高1.45倍。【结论】利用植物乳杆菌LK-1发酵辣木叶能大大提高GABA的含量。

【Objective】In this study, lactic acid bacteria were used as fermentation strains and to enrich GABA in Moringa oleifera liquid.【Method】First, the best strains from two commercial strains producing GABA and two trains isolated by the laboratory were evaluated. Then, by the single factor experiments, the effects of M. oleifera powder content, MSG content, the initial pH, the fermentation temperature and the fermentation time on the content of GABA was studied. The MSG addition amount, the initial pH, fermentation temperature and the fermentation time were orthogonalized to obtain the optimal fermentation conditions.【Result】The results showed that the abilities of the four lactic acid bacteria to produce GABA was as follows： Lactobacillus plantarum LK-1〉 Lactobacillus plantarum S35〉 Endococci 〉 Lactobacillus casei LK-1. The content of GABA in M. oleifera liquid fermented by Lactobacillus plantarum could be as high as 152 mg/L. According to the single factor and orthogonal experiments, the optimal fermentation conditions of GABA were as follows： 4% of Moringa powder, 4 g/L of MSG, initial pH 6.5, fermentation temperature of 35 °C, and fermentation time of 72 h. Under these conditions, the GABA content of the fermented M. oleifera liquid could be as high as 209 mg/L, which is 1.45 times higher than that the unfermented. 【Conclusion】The fermentation of Lactobacillus plantarum LK-1 was able to enhance the content of GABA in M. oleifera liquid