产γ-氨基丁酸乳酸菌的发酵条件优化

Optimization of Fermentation Conditions forγ-Aminobutyric Acid Production by Lactic Acid Bacteria

为了发掘特色酸乳中的优质乳酸菌资源,提高菌株的γ-氨基丁酸(γ-aminobutyric acid,GABA)产量,对前期一株分离自传统酸乳中的产GABA戊糖乳植杆菌(Lactiplantibacillus pentosus,L.pentosus)Z6-15,通过单因素试验及响应面设计法优化其GABA发酵工艺。结果表明,菌株的最佳发酵工艺:葡萄糖20 g/L、酵母粉10 g/L、蛋白胨11.5 g/L、乙酸钠5 g/L、L-谷氨酸钠(sodium hydrogen glutamate,L-MSG)4.5 g/L、K_(2)HPO_(4)2 g/L、柠檬酸三铵2 g/L、MnSO_(4)0.05 g/L、MgSO_(4)0.2 g/L、吐温-800.1%、初始pH值5.5,接种量4%、装添量175 mL,此优化条件下,菌株于37℃、160 r/min发酵培养72 h后,其GABA产量为3.96 g/L,较优化前提高了39.63%。

This study aimed to explore the high-quality lactic acid bacteria resources in traditional yoghurt,and improve the GABA production of these strains.The fermentation process of Lactiplantibacillus pentosus Z6-15,a GABA producing lactic acid bacteria isolated from traditional yogurt,was optimized using a single factor experiment and response surface methodology.The results showed that the optimum fermentation conditions were as follows:20 g/L glucose,10 g/L yeast powder,11.5 g/L peptone,5 g/L sodium acetate,4.5 g/L sodium hydrogen glutamate,2 g/L K_(2)HPO_(4),2 g/L triammonium citrate,0.05 g/L MnSO_(4),0.2 g/L MgSO_(4),0.1%Tween-80,an initial pH of 5.5,4%inoculum,and 175 mL dosage.Under the optimal fermentation conditions,the GABA yield was 3.96 g/L after 72 h fermentation at 37℃and 160 r/min,which was 39.63%higher than pre-optimization.