植物乳杆菌胞外多糖的分离纯化及其乳化特性  

Isolation, Purification and Emulsifying Properties of Exopolysaccharides Produced by Lactobacillus plantarum

作　　者：曹永强[1,2] 张健[1,2] 赵雯[1,2] 张彤赫 孙婧[1,2] 杨贞耐[1,2] 

机构地区：[1]北京食品营养与人类健康高精尖创新中心,北京工商大学,北京100048 [2]食品质量与安全北京实验室,北京工商大学,北京100048

出　　处：《食品科学》2016年第17期7-13,共7页Food Science

基　　金：国家自然科学基金面上项目(31371804);中国博士后科学基金项目(2015M580939)

摘　　要：在脱脂乳中分别培养植物乳杆菌菌株YW11和菌株SKT109,经三氯乙酸除蛋白、离心、乙醇沉淀、透析、冷冻干燥得到胞外多糖粗品,再经DEAE-Sepharose Fast Flow离子交换柱和Sepharose CL-6B凝胶柱纯化,得到两种胞外多糖纯品。利用气相色谱法分析此两种多糖的单糖组成,并采用KBr压片法观察红外光谱,利用动态光散射方法测定多糖的流体力学半径（Rh）。结果显示：YW11胞外多糖的单糖组成为葡萄糖、半乳糖,其物质的量比为3.45∶1,流体力学半径为69.20 nm;SKT109胞外多糖的单糖组成为葡萄糖、半乳糖,其物质的量比为1.43∶1,流体力学半径为41.74 nm;YW11胞外多糖的乳化能力强于SKT109胞外多糖,但前者的乳化稳定性略低;两种胞外多糖分别与其他乳化剂之间具有一定的协同作用,乳化颗粒的半径主要集中在1-2 μm之间。本研究获得的植物乳杆菌胞外多糖在食品加工中具有潜在的应用前景。In this study, Lactobacillus plantarum YW11 and SKT109 were separately incubated with skim milk. The crude exopolysaccharides（EPSs） produced by the 2 strains were prepared by adding the culture with trichloroacetic acid to remove proteins, followed by centrifugation, ethanol precipitation, dialysis and lyophilization, and they were further purified by successive DEAE-Sepharose Fast Flow ion-exchange chromatography and Sepharose CL-6B gel filtration chromatography. The monosaccharide composition of EPSs was analyzed by gas chromatography and their FT-IR spectra as well as hydrodynamic radii（Rh） were determined using a KBr disc technique and dynamic light scattering, respectively. The results showed that the EPS from strain YW11 was composed of glucose and galactose in a molar ratio of 3.45：1, and its Rh value was calculated as approximately 69.20 nm. On the other hand, the EPS from strain SKT109 was composed of glucose and galactose in a molar ratio of 1.43：1, and its Rh value was calculated as approximately 41.74 nm. The emulsifying capacity of the EPS from YW11 strain was higher, but its emulsifying stability was lower than that of the EPS from SKT109. Both EPSs had certain synergic emulsifying effects when either was mixed with other emulsifiers, with particle size of the emulsion particles being mainly in the range of 1–2 μm. The EPSs produced by L. plantarum in this study have potentially promising applications in food processing.

关 键 词：植物乳杆菌 胞外多糖 分离 纯化 乳化特性 

分 类 号：TS201.1[轻工技术与工程—食品科学]