TUBITAK Baskanlik, Bilim ve Toplum Daire Baskanligi, Ataturk Bulvari, Ankara, Turkey.
Microbiol Immunol. 2010 May;54(5):257-64. doi: 10.1111/j.1348-0421.2010.00219.x.
In the present study, the relationship between exopolysaccharide production and cholesterol removal rates of five strains of Lactobacillus delbrueckii subsp. bulgaricus isolated from home-made yoghurt was studied. Test strains were selected according to their exopolysaccharide production capacity. Influence of different bile concentrations on cholesterol removal was investigated. It was confirmed that B3, ATCC 11842 and G11 strains which produce high amounts of exopolysaccharide (211, 200 and 159 mg/l, respectively) were able to remove more cholesterol from the medium compared to those that produce low amounts of exopolysaccharide (B2, A13). The highest cholesterol removal (31%) was observed by strain L. delbrueckii subsp. bulgaricus B3, producing a high amount of exopolysaccharide, in 3 mg/ml bile concentration. Cholesterol removal by resting and dead cells was investigated and it was found to be 4%-14% and 3%-10%, respectively. Cholesterol removal by immobilized and free cells of the B3 strain was studied and it was determined that immobilized cells are more effective. Influence of cholesterol on exopolysaccharide production has also been tested and it was found that cholesterol increased the production of EPS. The results indicated that: (i) there is a correlation between cholesterol removal and EPS production; and (ii) L. delbrueckii subsp. bulgaricus B3 is regarded as a suitable candidate probiotic and adjunct culture.
在本研究中，研究了从自制酸奶中分离出的五株德氏乳杆菌保加利亚亚种（Lactobacillus delbrueckii subsp. bulgaricus）的胞外多糖（EPS）产量与胆固醇去除率之间的关系。根据 EPS 产量选择测试菌株，研究了不同胆盐浓度对胆固醇去除的影响。结果证实，能够产生大量 EPS（分别为 211、200 和 159mg/L）的 B3、ATCC 11842 和 G11 菌株比那些产生少量 EPS（B2、A13）的菌株能从培养基中去除更多的胆固醇。在 3mg/ml 胆盐浓度下，产生大量 EPS 的保加利亚乳杆菌 B3 菌株的胆固醇去除率最高（31%）。研究了静止和死亡细胞的胆固醇去除情况，发现分别为 4%-14%和 3%-10%。研究了 B3 菌株固定化和游离细胞的胆固醇去除情况，结果表明固定化细胞更有效。还测试了胆固醇对 EPS 产量的影响，发现胆固醇增加了 EPS 的产量。结果表明：（i）胆固醇去除率与 EPS 产量之间存在相关性；（ii）保加利亚乳杆菌 B3 可作为合适的候选益生菌和辅助培养物。
