【摘要】 从婴儿粪便和药品中筛选到耐酸和胆汁盐的2株双歧杆菌菌种,分别命名为Bi.bifidumWN 04与Bi.longumGB 03.在pH值2.0条件下培养2h后再于胆汁盐质量浓度1.0g/dL的条件下培养2h.2株菌在pH值分别为2.0和3.0的50mmol/L的磷酸盐缓冲液中存活率较高;在胆汁盐质量浓度分别为0.25,0.5,1.0g/dL和2.0g/dL,pH值为6.8的50mmol/L磷酸盐缓冲液中存活率也较高,胆汁盐耐受性没有明显区别.在4℃保存于新鲜牛乳中,Bi.bifidumWN 04能够在8周内保持最高活菌数[lg(CFU/mL)>9],其它菌种活菌数[lg(CFU/mL)]<8.更多还原

【Abstract】 Low pH and high bile salts resistant strains of Bifidobacterium were isolated from infant feces and a pharmaceutical product. Strains were firstly pre-enriched in Raffinose Bifidobacterium (RB) medium before stressed in an acid (pH 3.0) and then in 1.0 g/dL bile salt for 2 hr. Two isolates, designated Bi. longum GB-03 and Bi. bifidum WN-04, showed considerably high survival rates when incubated in 50 mmol phosphate buffer solution with pH (2.0) or 3.0. The survival rate was also high in the same buffer solution (pH 6.8) containing oxgall of 0.25, 0.5, 1.0 and 2.0 g/dL. Both isolates were not significantly different in the survial properties when tested at these different bile salts concentrations. All strains tested had similar growth rates at pH 4.5. Bi. bifidum WN-04 showed high culture stability (lg CFU/mL>9)when grown in fresh milk at 4 ℃, while all others declined below 8.更多还原