泡菜中1株高产γ-氨基丁酸且具有抗菌性乳酸菌株的筛选和鉴定

Screening and identification of lactic acid bacteria with GABA producing and antimicrobial activity from Paocai

利用薄层层析法从泡菜乳酸菌中筛选出1株高产γ-氨基丁酸(γ-aminobutyric acid,GABA)的菌株,通过API50CHL糖发酵测定、16S r DNA序列分析鉴定该菌为短乳杆菌,并命名为短乳杆菌(Lactobacillus brevis)PD1-2。经高效液相色谱法定量测定,该菌在含10 g/L谷氨酸钠(sodium glutamate,MSG)的MRS培养基中发酵48 h,生产GABA的转化率达100%;在含50 g/L MSG的MRS培养基中发酵72 h,GABA的转化率达93.7%。通过抗菌性实验发现,该菌对革兰氏阳性菌的藤黄微球菌、枯草芽孢杆菌、蜡状芽孢杆菌、单增李斯特菌和革兰氏阴性菌的大肠杆菌均具有抗菌性,且初步确定抑菌物质为细菌素。

One γ-aminobutyric acid（ GABA） producing lactic acid bacteria（ LAB） strain isolated from paocaiwas confirmed by thin layer chromatography（ TLC） test. This strain was identified by API test and 16 S r DNA sequencinganalysis,and named as Lactobacillus brevis PD1-2. Through high performance liquid chromatography（ HPLC） analysis,the quantitative results showed that 100% sodium glutamate（ MSG） could be converted to GABA in MRS medium with 10 g / L MSG at 48 hours; and conversion rate reached to 93. 7% in MRS medium with 50 g / L MSG at 72 hours. Through antimicrobial test,PD1-2 revealed inhibitory activity against Gram-positive and Gram-negative bacteria,including Micrococcus luteus,Bacillus subtilis,Bacillus cereus,Listeria monocytogenes and Escherichia coli,and the antimicrobial substance was confirmed as bacteriocin. This study could provide the foundation for producing and application of the interrelated metabolites by PD1-2.