Thirteen strains of Lactobacillus acidophilus of various origins were tested for bile salt hydrolase (BSH) activity, growth characteristics and surface properties during cultivation in the presence of ox bile. Seven strains were BSH positive, three strains were found to hydrolyse both sodium glycocholate and taurocholate and four hydrolysed only glycocholate. The addition of ox bile (3; 5 or 10 g/l) to MRS growth medium affected the growth rate of both BSH-positive and BSH-negative strains. The lag phases were increased when 5 or 10 g/l of ox bile were added. Growth rates and lag phases were significantly different between BSH-positive and BSH-negative strains in MRS medium with bile. BSH-positive strains were better able to adapt to increasing bile concentrations. The concentration of 2 g/l sodium cholate completely inhibited growth of all lactobacilli tested. Its toxicity was influenced by pH of medium. The addition of 3 g/l ox bile affected the properties related to ability of lactobacilli to adhere to surfaces––autoaggregation increased in all strains and zeta potential only in BSH-negative strains. In all strains tested, bshA and bshB genes were identified with the exception of L. acidophilus Lafti-L10. Repeated cultivation in MRS with bile did not cause the expression of genes in BSH-negative strains.

中文翻译：

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嗜酸乳杆菌的胆汁盐水解酶活性，生长特性和表面性质

十三株嗜酸乳杆菌在牛胆的存在下培养期间，对不同来源的胆汁盐水解酶（BSH）活性，生长特性和表面性质进行了测试。7株是BSH阳性，发现3株同时水解了糖胆酸钠和牛磺胆酸钠，有4株只水解了糖胆酸钠。向MRS生长培养基中添加牛胆汁（3; 5或10 g / l）影响BSH阳性和BSH阴性菌株的生长速率。当添加5或10 g / l牛胆汁时，滞后阶段增加。在带有胆汁的MRS培养基中，BSH阳性菌株和BSH阴性菌株之间的生长速率和滞后阶段显着不同。BSH阳性菌株更能适应不断增加的胆汁浓度。2 g / l胆酸钠的浓度完全抑制了所有乳杆菌的生长经过测试。其毒性受培养基pH值的影响。添加3 g / l的牛胆汁会影响与乳杆菌粘附到表面的能力有关的特性-所有菌株中的自动聚集增加，仅BSH阴性菌株中的zeta电位增加。在所有测试的菌株中，除嗜酸乳杆菌Lafti-L10外，均鉴定了bshA和bshB基因。在具有胆汁的MRS中重复培养不会引起BSH阴性菌株中基因的表达。