胆汁酸盐和低pH值对乳酸菌活性的影响

EFFECT OF BILE AND LOW PH ON THE ABILITY OF LACTIC ACIDBACTERIUM TO SURVIVE

本文比较了几种乳酸菌对胆汁酸盐的耐受性和ｐＨ值的残活能力。研究结果表明，在０．２％的ＭＲＳ或ＢＭ培养基上，婴儿双歧杆菌的生长速率受到的抑制最小，依次为嗜酸乳杆菌、保加利亚乳杆菌和嗜热链球菌。胆汁酸盐对其生长的完全抑制浓度分别为１．５％、１．２％、０．５％和０．３％。在ｐＨ３时，嗜热链球菌活菌数量降低较为明显，在ｐＨ２时，在３７℃１ｈ过程中，婴儿双歧杆菌活菌数量基本不变；嗜酸乳杆菌在３７℃２０ｍｉｎ后，活菌数量迅速降低；保加利亚乳杆菌数量在３７℃２０ｍｉｎ时几乎为零。

Lactic acid bacterium were evaluated to determine the bile tolerance and low pH on the ability to survive in broth. Various lactic acid bacterium varied in their ability to grow in MRS or BMbroth containing 0.2% oxgall compared with control broth. Bile tolerance concentration of B. infantis.L. acidophilus. L. bulgaricus and S. thermophilus were 1.5%. 1 .2%. 0.5% and 0.3%, respectively. Theywere suspended in MRS broth at PH 2,3 and 4 incubated 37t for 1h. At PH 4 in broth, the number ofcells were no signifucatly reduced in 1 h. At PH 3, viable cells of S. thermophilus was reduced rapidly after 20 min. At PH2, no viable cells were recovered after 30min except B. inf antis.