产γ-氨基丁酸乳酸菌的高密度培养条件优化

Optimization of High Density Culture Conditions for GABA-producing Lactic acid Bacteria

γ-氨基丁酸(GABA)是一种非蛋白氨基酸,作为重要的抑制性神经递质在中枢神经系统中发挥重要作用,可用于治疗癫痫、精神分裂症、焦虑症等各种神经系统疾病,而GABA作为一种新型功能性食品成分也得到了广泛认同,所以研制产GABA的直投式菌剂,在富含GABA的发酵食品应用中有重要意义。采用单因素试验和响应面试验对产GABA的植物乳杆菌LP-YX-1进行培养基和培养条件优化,得到最佳培养基配方和培养条件为葡萄糖质量浓度45.44 g/L,蛋白胨质量浓度54.46 g/L,酵母粉质量浓度17.37 g/L,接种量3%,初始pH值8.0,培养时间24 h,此时培养液活菌数达到3×10^(9) CFU/mL,比优化前提高了2.325倍。添加保护剂后,对培养液进行冷冻干燥制备冻干直投式菌剂,其活菌数达9.74×10^(11) CFU/g,存活率为83.33%。

γ-aminobutyric acid(GABA)is a non-protein amino acid,as an important inhibitory neurotransmitter plays an important role in the central nervous system,can be used to treat epilepsy,schizophrenia,anxiety and other neurological diseases,GABA as a new functional food component has also been widely recognized.Therefore,it is of great significance to develop gabA-producing directly delivered bactericides in the application of gabA-rich fermented foods.Single factor and response surface methodology were used to optimize the medium and culture conditions of Lactobacillus plantarum LP-YX-1 producing GABA,and the optimal medium formula and culture conditions were obtained as follows:glucose 45.44 g/L,peptone 54.46 g/L,yeast powder 17.37 g/L,3%inoculation amount,initial pH 8.0,culture time 24 hours.The number of viable bacteria in the culture medium reached 3×10^(9) CFU/mL,which was 2.325 times higher than that before optimization.After adding protective agent,the culture medium was freeze-dried to prepare the lyophilized bacteria agent.The viable bacteria count was 9.74×10^(11) CFU/g,and the survival rate was 83.33%.