四川泡菜中产γ-氨基丁酸植物乳杆菌BC114发酵条件优化

摘要

为拓展产γ-氨基丁酸(γ-aminobutyric acid,GABA)微生物资源,以四川泡菜为分离源,从中分离具有产GABA能力的乳酸菌,并对其进行发酵条件优化.通过高效液相色谱法对筛选到的GABA菌株进行表达能力评估发现,菌株BC114在含10 g/L L-谷氨酸钠的MRS培养基于37℃发酵48 h后,发酵液中GABA质量浓度为1.72 g/L.以MRS培养基为基础培养基,采用单因素试验和响应面中心组合试验设计对发酵条件进行优化,得到最适培养基组成为葡萄糖15 g/L、牛肉膏10 g/L、蛋白胨10 g/L、酵母膏5 g/L、柠檬酸三铵2 g/L、K2 HP041.50g/L、L-谷氨酸钠17 g/L、乙酸钠5 g/L、MnSO40.05 g/L、MgSO40.10 g/L、吐温-80 1 mL/L;培养条件为pH 5.50、发酵温度37℃、发酵时间80 h、接种量4％.在此优化条件下,植物乳杆菌BC114产GABA能力达到3.82 g/L,较优化前提高了2.22倍.%The aim of the present study was to optimize the fermentation conditions of γ-aminobutyric acid (GA-BA)-producing by lactic acid bacteria from Sichuan Pickle.The performance of GABA-producing strains was evaluated by high performance liquid chromatography (HPLC) method.The results showed that strain BC114 had the higher GABA-producing ability (1.72 g/L) in MRS broth with 10 g/L initial glutamic acid after fermented at 37 ℃ for 48 h.On the basis of MRS culture medium,fermentation conditions of Lactobacillus plantarum BC114 for GABA were optimized by response surface central composite design (CCD).The results showed that the optimal fermentation medium was comprised of glucose 15 g/L,beef extract 10 g/L,peptone 10 g/L,yeast extract 5 g/L,trisodium amine 2 g/L,dipotassium phosphate 1.50 g/L,L-glutamate 17 g/L,sodium acetate 5 g/L,manganese sulfate 0.05 g/L,magnesium sulfate 0.10 g/L,and Twain-80 1 mL/L.And the optimal fermentation condition was as follows:pH 5.50,fermentation temperature 37 ℃,fermentation time 80 h and inoculum amount 4％.Under the optimized conditions,the production of GABA by L.plantarum BC114 reached 3.82 g/L,which was 2.22-fold higher than that before the optimization.