耐消化道逆环境双歧杆菌优良菌株的筛选  

Isolation of novel Bifidobacterium strains with tolerance of gastrointestinal environment

作　　者：江志杰[1] 李平兰[1] 孙成虎[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《中国农业大学学报》2005年第2期6-10,共5页Journal of China Agricultural University

基　　金：国家 8 6 3计划资助项目 (2 0 0 2AA2 4 80 4 1)

摘　　要：筛选耐消化道逆环境的优良双歧杆菌菌株,以来源于母乳婴儿粪便、未断奶仔猪粪便、市售双歧杆菌制剂和本实验室保存的双歧杆菌为出发菌株,采用改良MRS液体培养基,模拟人体胃肠道逆环境,对其耐消化道逆环境特性进行了研究。通过耐酸(pH3的PBS)、耐胆汁酸盐(质量浓度1～2 0mg/mL)试验对初筛得到的14株菌株进行复筛,得6株菌株,它们在pH3条件下作用12 0min后存活率均>93% ,活菌数均>10 8cfu/mL ;在含5mg/mL牛胆酸钠的改良MRS液体培养基中作用2 4h后活菌数仍>10 6cfu/mL ,除J12和B0 3外,其他4株在含2 0mg/mL牛胆酸钠的改良MRS液体培养基中作用2 4h仍有活菌被检出(活菌数>10 4cfu/mL)。在此基础上,采用胃蛋白酶和胰蛋白酶模拟胃肠液得3株耐消化道酶菌株A0 3、A0 4和L 1,在含5mg/mL胃蛋白酶的PBS培养基(pH3)作用12 0min后其活菌数均高达约10 8cfu/mL ,而在含10mg/mL胰蛋白酶的改良MRS液体培养基作用2 4h后,其活菌数均高达约10 9cfu/mL ;这2种消化道酶对其几乎没有抑制作用。研究结果表明,双歧杆菌A0 3、A0 4和L 1菌株耐受消化道逆环境的能力最好,可用做微生态制剂菌株。A large culture collection of bifidobacteria （61 strains） was screened or activated from infant fecal samples, un-ablactated pig fecal samples, biotechnological preparations and Bifidobacterium strains conserved in the lab. Using CMRS medium, the intolerance ability of Bifidobacterium strains was studied in imitating gastroenteric environments. Fourteen strains were gained by the first screening; whereas only six obtained by the second screening （pH3 PBS, ] - 20 mg/mL bile salt concentration）. Their survivability was above 93% and the living bacterial number was above 10s cfu/mL after in pH3 condition and above 10^6cfu/mL after 24 h in .5 mg/mL bile salt CMRS. Furthermore, B02, A03, A04 and L^-1 could survive at 2 g/kg bile salt （ 〉104 cfu/mL）. Ultimately A03, A04 and L^-1 show more Ionganimous to pepsin and pancreatin than others. The living bacterial number was about 108 cfu/mL after 1.5 h in simulative gastric juice containing 5 mg/mL pepsin, and was about 109 cfu/mL after 24 h in simulative intestinal juice containing 1% pancreatin. The result shows that gastrointestinal tract tolerance ability of different Bifidobacterium strains was different; the tolerances of A03, A04 and L^-1 were excellent ones among the tested strains, which have a latent ability as the strains of Mirobial Ecological Agents.

关 键 词：双歧杆菌 消化道 耐性 筛选 

分 类 号：Q939.117[生物学—微生物学] R978.1[医药卫生—药品]