从四川传统萝卜泡菜母水中分离出优势乳酸菌,对其进行鉴定和发酵特性研究.用纯培养的方法对菌株进行分离纯化,经生理生化实验和16S rDNA测序对菌种进行鉴定.对照类肠膜魏斯氏菌(Weissella parames-enteroides),研究其生长特性、耐受性和降解亚硝酸盐能力,评价筛选菌株的发酵特性,并采用气相色谱-离子迁移谱对菌株产挥发性风味物质的能力进行检测分析.筛选出L2、L3、L7、L15和L24等5株菌分别为:布氏乳杆菌(Lactobacillus buchneri)、短乳杆菌(Lactobacillus brevis)、乳酸片球菌(Pediococcus acidilactici)、植物乳植杆菌(Lac-tiplantibacillus plantarun)和鼠李糖乳酪杆菌(Lacticaseibacillus rhamnosus).L15 和 L24 生长速度比其他菌株快;菌株L7、L15和L24产酸能力强;菌株L15和L24对NaCl的耐受性最好;菌株L7的NaNO2耐受性最差;5种菌株降解亚硝酸盐的能力均高于90%.5株乳酸菌产挥发性物质的特征不同,L3产酮类物质相对含量最高,L15样品中醇类物质的相对含量最高,L24样品中酯类物质的相对含量最高.综上,5种乳酸菌均具有发酵泡菜潜能,可作为泡菜功能微生物资源.
The dominant lactic acid bacteria(LAB)strains were isolated and identified from the traditional fermented Sichuan radish pickle brines,and their fermentation characteristics were examined.Isolated strains were identified by physiological and biochemical ex-periments,as well as 16S rDNA sequencing.The fermentation characteristics of the strains were evaluated including their growth perform-ance,tolerance to salt and nitrite and nitrite degradation capability,compared to strain Weissella paramesenteroides.Gas chromatography-ion mobility spectroscopy(GC-IMS)was used to detect and analyze the volatile flavor substances to evaluate the flavor-producing capabili-ty of the strains.Isolated LAB strains L2,L3,L7,L15,and L24 were identified respectively as Lactobacillus buchneri,Lactobacillus bre-vis,Pediococcus acidilactici,Lactiplantibacillus plantarun and Lacticaseibacillus rhamnosus.Strains LI 5 and L24 grew faster than others.Strains L7,L15,and L24 showed stronger acid production capability.Strains L15 and L24 showed better tolerance to NaCl.Strain L7 showed the worst tolerance to sodium nitrite.All five strains showed capability to degrade nitrite by more than 90%.The volatile sub-stances produced by the five strains were different.L3 produced the highest content of ketones.L15 produced the highest relative content of alcohols.L24 produced the highest relative content of esters.In summary,all five lactic acid bacteria have the potential to ferment pickles and can be used as functional microbial resources for pickle production.