藏灵菇酵母菌M3耐胃肠道逆环境特性及降胆固醇的实验研究

Study on Tolerance Characteristics of the Gastrointestinal Tract and Cholesterol-Lowering Effects of Kluyveromyces marxianus M3 from Tibetan Kefir

利用从藏灵菇中筛选的马克斯克鲁维酵母M3菌株探讨胃肠道耐受性及体外降胆固醇功效。分别在pH1．5～4．5、胆盐浓度0.3％～3．0％、NaCl浓度3．0%-6．0％的模拟胃肠道环境下，采用活菌计数法检测M3菌株的耐胃肠道逆环境特性，以邻苯二甲醛法检测其降胆固醇效果。结果表明：在pH1．5-4．5作用4h活菌数可达10^6cfu／ml，0．3％～3．0％胆盐及3．0％～6．0％NaCl作用8h活菌数可达10^5-10^6cfu／ml，在pH1．5～3．0（4h）及胆盐浓度0．3％～3．0％的模拟人体胃肠道环境下降胆固醇率均在60％以上。显示M3菌株具有较强的耐胃肠道逆环境特性及良好的降胆固醇能力，为开发研制降胆固醇功能食品及微生态制剂提供了试验基础。

Using Kluyveromyces marxianus M3 isolated from Tibetan Kefir to study tolerance characteristics of the gastrointestinal tract and cholesterol-lowering effects in vitro. Viable count was used to detect M3 stains＇ tolerance characteristics of the gastrointestinal tract separately under simulated gastrointestinal tract environment pH 1.5-4.5, salt concentration 0.3%-3.0%, sodium chloride 3.0%-6.0%. At the same time, using O-phthalaldehyde to detect the effect of its cholesterol-lowering. The result shows that after 4 hours under pH 1.5-4.5 the viable can get 10^6 cfu/ml. The viable can be 10^5-10^6 cfu/ml under 0.3%-3.0% bovine bile salt and 3.0%-6.0% sodium chloride （8 h）. Also, in the simulated gastrointestinal tract environment pH 1.5-3.0 （4 h）, salt concentration 0.3%-3.0% （8 h） the cholesterol-lowering can reach 60%. M3 strains have strong tolerance characteristics against the environment of the gastrointestinal tract and the good cholesterol-lowering ability, which provide the experimental basis for the development of cholesterol-lowering functional foods and probiotics＇ study.