【摘要】 本实验对双歧杆菌22-5胞外多糖(exopolysaccharide,EPS)进行了纯度鉴定,并进一步研究了其分子量、酸碱性、溶解度、黏度等理化性质。结果表明:该EPS是一种组分单一的不含游离核酸和蛋白质的多糖物质,分子量为1.1×105D,偏酸性,pH6.5,易溶于水,难溶于有机溶剂,是一种热不可逆凝胶,黏度受EPS浓度、温度影响明显,在pH4.0～10.0之间稳定,离子强度对其影响不大。更多还原

【Abstract】 The purity and some physicochemical properties of EPS (exopolysaccharide) by Bifidobacterium astroides 22-5 are studied. The result showed that the EPS is an onefold polysaccharide without dissociative nucleic acid and protein ,whose molecular mass 1.1×105 D, acidity , pH 6.5, soluble in water, but indissoluble in organic solvent.solubility. The viscosity of EPS is negatively correlated with temperature. Besides, it is stable when the pH of environment varies in the range from 4 to 10 and the ironic intensity is changed更多还原