【摘要】 益生菌是对人体健康具有促进作用的活性微生物,具有食用安全性。从酸乳制品中筛选出一株具有产γ-氨基丁酸能力较高的菌株,经形态学观察、生理生化检验和16S r DNA序列分析,初步鉴定为短乳杆菌(Lactobacillus brevis),属益生菌范畴。经培养基和发酵条件优化,发酵液中γ-氨基丁酸的含量可达2.03 g/L。以该菌株为出发菌株进行紫外诱变处理,得到一株突变菌株,γ-氨基丁酸产量达2.31 g/L,与出发菌株相比提高了11.4%。经过多次传代,稳定性较好。研究结果有助于拓宽益生菌产品应用领域。更多还原

【Abstract】 Probiotics are live micro-organisms with edible safety and beneficial to human health.A γ-aminobutyric acid(GABA) producing strain was isolated from yogurt samples. Based on 16 S r DNA sequence, phylogenetic analysis, morphological and physiological characterization, the strain was identified as Lactobacillus brevi, which belongs to the category of probiotics. The yield of GABA reached 2.03 g/L after optimization of culture conditions and media components. Ultraviolet irradiation was used to treat the original strain. The accumulation of GABA was 2.31 g/L, which was increased 11.4% compared with that of original strain. The mutant GABA-producing strain was stable after several generations. These results showed that the application field of probiotic products could be broadened.更多还原