摘要
干酪乳杆菌LC2W发酵脱脂乳上清液通过添加三氯乙酸除蛋白,酒精沉淀得粗胞外多糖LCP;粗多糖LCP经DE-AE-SepharoseFF离子交换柱分离得到三个组分(LCP1、LCP2和LCP3),主要组分LCP1经高效体积排阻色谱和毛细管电泳鉴定为均一组分,分子量为3.27×106Da。紫外光谱测定表明:LCP1不含蛋白质和核酸;红外光谱测定表明:LCP1具有多糖的特征吸收峰;气相色谱测其单糖组成(质量比)为鼠李糖:半乳糖:葡萄糖=0.4353∶0.2514∶1。
Crude exopolysaccharides LCP were prepared from cell-free whey of skim milk fermented by Lactobacillus casei LC2W by eliminating proteins with trichloroacetic acid and precipitating with cold ethanol. LCP were separated into three fractions （ LCP1, LCP2 and LCP3 ） by anion exchange chromatography DEAE-Sepharose FF. The main fraction LCP1 of exopolysaccharides, with a molecular weight of 3.27 × 10^6 Da, was identified to be a homogeneous component by high-performance size-exclusion chromatography and capillary electrophoresis, contained no protein and nucleic acid by UV spectra, which had characteristic absorbance peaks of polysaccharide in the FT-IR spectra. It was composed of rhamnose, galacrose and glucose by gas chromatography, and their ratio was 0.4353 ： 0.2514： 1.
出处
《食品与机械》
CSCD
北大核心
2007年第1期9-11,43,共4页
Food and Machinery
基金
上海市科技兴农重点攻关项目(沪农科攻字(2004)第11-1号)
关键词
干酪乳杆菌
胞外多糖
分离纯化
性质
Lactobacillus casei
Exopolysaccharides
Separation and purification
Characterization
