摘要
目的:研究产胆盐水解酶植物乳杆菌H13的耐酸、耐胆盐特性,在此基础上对其可能的降胆固醇作用机理进行体外试验研究。方法:采用MRS培养基,模拟人体胃酸环境(pH=3)和胆盐环境(0.3%),测定H13菌株在酸性及高胆盐环境作用后的存活菌数,并在此胆盐浓度下测定植物乳杆菌H13的胆盐水解酶活力、降解胆盐能力和胆固醇沉淀量。结果:菌体能够耐受pH3的环境和0.3%的胆盐环境;该菌产生的胆盐水解酶在降低胆固醇方面具有重要作用,酶活性与游离胆酸量、胆固醇沉淀量呈正相关,而且胆盐水解酶对反应底物的特异性不同,以甘氨胆酸钠为佳。结论:植物乳杆菌H13体外降胆固醇作用的机理主要是其产生的胆盐水解酶使胆盐失去共轭作用,在酸性(pH<6.0)条件下,解共轭胆盐与胆固醇形成复合物共同沉淀下来。
Objective ： In this study, the acid and bile salt resistant ability of L. plantarum H13 producing bile salt hydrolase and its possible cholesterol-reducing mechanism in vitro were investigated. Methods： By stimulating human gastric acid and intestinal bile salt condition, the viability of H13 strain during exposure to acid MRS broth （pH=3） and bile salt MRS broth （0.3%） were determined respectively. Then the bile salt hydrolase activity of H13 strain, degradation of bile salt and cholesterol precipitation were measured in this bile salt concentration. Results： H13 strain had tolerance capability to the pH=3 environment and 0.3% concentration of bile salt. Bile salt hydrelase produced by H13 strain had an significant impact on reducing cholesterol. It showed that there was positive correlation with enzymic activity, free bile acid and cholesterol precipitation. This bile salt hydrolase showed substrate specificity and sodium glycocholate was better. Conclusion： The main mechanism for the in vitro reducing cholesterol by LactobaciUus plantarum H13 was related to the bile salt hydrolase activity of the cells, and releasing unconjugated bile acids induced cholesterol coprecipitation at low pH values.
出处
《中国食品学报》
EI
CAS
CSCD
北大核心
2009年第5期24-28,共5页
Journal of Chinese Institute Of Food Science and Technology
基金
国家863项目(2006AA10Z343)
"十一五"科技支撑项目(2006BAD05A03)
关键词
植物乳杆菌
胆盐水解酶
降胆固醇
共沉淀
lactobacillus plantarum
bile salt hydrolase
cholesterol-reducing
coprecipitation
