本研究目的為應用台灣酸菜中篩選的高gama-胺基丁酸 (γ-aminobutyric acid; GABA) 生產菌種Lactobacillus brevis SF-1，探討其生產GABA的最適條件。首先在固定100 mM麩氨酸、接菌量106 CFU/ml及50 μM 5'-磷酸酛哆醛 (Pyridoxal 5’-phosphate; PLP) 之下，以反應曲面法探討培養溫度25-35℃ 及起始pH 6.0-7.0對GABA產量的影響； 結果顯示最適培養條件為培養溫度31.8℃ 及起始pH 6.6，可得最高GABA產量，其預測值為10,659 mg/L，而實際產量為10,481 mg/L，預測值在試驗值的95%信心度區間之內。其次，分別探討麩胺酸濃度、PLP濃度以及接菌量對於GABA產量之影響；提升麩胺酸濃度從100 mM至400 mM及菌株接菌量從106至108 CFU/ml均可顯著提升GABA產量，而添加0~100 μM PLP則不影響產量。在上述最佳條件下培養SF-1四天之GABA產量為17,742 mg/L。為了進一步了解此菌株生產更多GABA的潛力，根據文獻研究的比對延長培養時間至六天，並探討400~ 1,000 mM麩胺酸添加量對GABA產量的影響；結果以添加500 mM麩胺酸及培養六天之產量最高可達43,286 mg/L。

The aim of this study was to apply Lactobacillus brevis SF-1 with higher production activity of gama-aminobutyric acid (GABA) isolated from pickled mustard in Taiwan to investigate its optimum conditions for GABA production. At first, response surface methodology was used to evaluate the independent variables including cultivation temperature 25-35℃ and initial cultivation pH 6.0-7.0 under fixed 100 mM glutamic acid, inoculation concentration of 106 CFU/ml and 50 μM PLP. The results indicated optimum cultivation conditions for maximizing GABA production were 31.8℃ and pH 6.6. The maximum predicted value of 10,659 mg GABA/L could be achieved within 95% confidence interval of experimental value of 10,481 mg GABA/L. And then, the effects of glutamic acid concentration, cell inoculation concentration and PLP concentration were further investigated. Both increase of glutamic acid concentration from 100 to 400 mM and inoculation concentration from 106 to 108 CFU/ml, respectively, could significantly produce GABA to 17,742 mg/L, but not affected by addition of 0-100 μM PLP. To understand more potential increase of GABA production for SF-1, cultivation time of six days instead of four days along with 400~1,000 mM glutamic acid concentration were investigated. The results suggested that higher GABA production of 43,286 mg/L was achieved by addition of 500 mM glutamic acid.