【摘要】 本文对干酪乳杆菌KW3产生的胞外多糖的流变性、乳化性质及免疫调节和降血压等生物活性进行研究。试验结果表明:高浓度KW3EPS溶液呈剪切变稀,而在低浓度时剪切速率对黏度没有影响;溶液黏度随温度升高明显下降;随着pH值的增大溶液黏度升高,当pH值增至偏碱性时,溶液黏度呈下降趋势;低浓度的盐可降低溶液黏度;黏弹性研究显示:KW3EPS溶液不能形成胶体;乳化试验表明其具有良好的乳化活性和乳化稳定性。动物实验表明KW3EPS能显著刺激淋巴细胞增殖;当其质量浓度为200μg/mL时,巨噬细胞产生的NO量最大,吞噬功能最强。KW3EPS还能显著降低SHR大鼠的动脉收缩压(P<0.01)及主动脉ACE活性,而对肺、肾及血清中ACE活力没有明显影响。更多还原

【Abstract】 The rheology characteration and bioactivity of exopolysaccharides from Lactobacillus casei KW3 were tested in this study. Steady-shear rheological measurements of KW3 EPS showed a non-Newtonian shear-thinning flow behavior at high concentrations and a Newtonian flow behavior at low concentrations. The apparent viscosity increased with the increase of pH value in the acidic and neutral condition. Low concentration of salt might reduce the viscosity of KW3 EPS. Viscoelastic tests proved KW3 EPS could not form a gel. Also, good emulsion activity and emulsion stability of KW3 EPS was proved. In immunological test, KW3 EPS showed potent stimulating effects on murine lymphocyte proliferation and can enhance macrophage phagocytosis. The NO production reached highest when the concentration of polysaccharide was 200 μg/mL, meanwhile, the phagocytosis function was the strongest. Additionally, the results showed that KW3 EPS produced a significant decrease in the systolic blood pressure(SBP) of SHR(P<0.01), and reduced ACE activity in aorta but no effects on ACE activity in the lung, kidney and blood seurum.更多还原