模拟人体胃肠道环境筛选益生乳杆菌  

Screening of probiotic Lactobacillus in simulated gastrointestinal environment

作　　者：赵芳[1] 李艳琴[1] 李彬春[1] 

机构地区：[1]山西大学生物技术研究所化学生物学与分子工程教育部重点实验室,山西太原030006

出　　处：《微生物学通报》2016年第6期1396-1403,共8页Microbiology China

基　　金：国家自然科学基金项目(No.31400684);山西省基础研究项目(No.2014021030-3);山西大学引进人才建设项目(No.206533801001)~~

摘　　要：【目的】筛选具有益生特性的乳杆菌作为保健型酸奶的候选菌株。【方法】从健康人肠道和奶豆腐中分离筛选出耐受人工胃液的乳杆菌,对其进行体外益生特性(人工胃肠液耐受性、胆盐耐受性、抑菌活性及胆固醇降解能力)研究。【结果】从在乳杆菌分离培养基上有溶钙圈的41株菌株中筛选出5株耐酸、耐人工胃液较强的菌株,经16S rR NA基因测序鉴定,其中3株为乳杆菌,分别命名为植物乳杆菌Lp MT-3、植物乳杆菌Lp MT-5和唾液乳杆菌LsA F-7。在人工胃液中3株菌的耐受力均强于商品化的对照菌株LGG(鼠李糖乳杆菌GG);转入肠液4 h后直至26 h,Lp MT-5存活率基本稳定在45%左右,仅次于LGG。胆盐浓度为0.10%时,3株乳杆菌的耐胆盐能力均强于LGG;胆盐浓度为0.20%时,Lp MT-3和LsA F-7仍能存活。3株乳杆菌均具有抑菌活性,对粪肠球菌的抑制最明显,其次是金黄色葡萄球菌,对大肠杆菌、沙门氏菌的抑制作用较差。3株乳杆菌对胆固醇的清除效力依次为Lp MT-3>LpM T-5>Ls AF-7;清除率依次为Ls AF-7>Lp MT-3>LpM T-5。【结论】筛选出3株适应人体胃肠液环境、耐胆盐、抑菌及降胆固醇活力强的乳杆菌,可作为进一步开发新的益生菌产品和保健型酸奶的菌株。[Objective] To screen probiotic Lactobacillus as candidate strains for healthy yoghurt. [Methods] Lactobacilli isolated from healthy human feces and Milk Tofu were tested and screened by tolerance to simulated gastric juice. Probiotic potential was determined based on resistance to simulated gastrointestinal juice and bile salts, antibacterial activity, and cholesterol degradation ability. [Results] Results show that 41 bacterial strains with dissolved calcium were obtained from the Lactobacillusisolation medium. Five strains with high tolerance to low p H and simulated gastric juice were selected from the screened strains and identified by 16 S rR NA gene sequencing. Three strains were Lactobacillus, named as Lactobacillus plantarum（LpM T-3）, Lactobacillus plantarum（Lp MT-5） and Lactobacillus salivarius（Ls AF-7）. These three Lactobacillus strains exhibited higher tolerance to simulated gastric juice than the commercially available LGG（Lactobacillus rhamnosus GG）. After the Lactobacillus strains were transferred to intestinal juice for 26 h, survival rate of Lp MT-5 was stable at approximately 45%, lower than LGG（49%）. The three Lactobacillus strains displayed higher tolerance to bile salt than LGG when the concentration of bile salt was 0.10%. Lp MT-3 and Ls AF-7 were still alive when the concentration of bile salt was increased to 0.20%. All the three strains exhibited antibacterial activity, especially to Enterococcus faecalis, followed by Staphylococcus aureus, and the least inhibition effect to Escherichia coli and Salmonella. All three Lactobacillus strains also showed cholesterol-reducing ability. [Conclusion] Three strains of Lactobacillus could be taken as the strains to further develop new probiotic products and health yogurt.

关 键 词：分离筛选 乳杆菌 人工胃肠液耐受性 胆盐耐受性 降胆固醇 

分 类 号：R371[医药卫生—病原生物学]