胆盐水解酶基因在植物乳杆菌ST-Ⅲ中的表达

Gene expression of the bile salt hydrolase in Lactobacillus plantarum ST- Ⅲ

摘要: 胆盐水解酶（Bile salt hydrolase,BSH）是微生物生长、繁殖过程中产生的一种胞内酶,因其与降低血胆固醇、预防心血管疾病有关而受到广泛关注。本研究通过基因工程技术实现了4种胆盐水解酶基因在Lactobacillus plantarum ST-Ⅲ的过表达,并利用茚三酮显色法测定了表达4种BSHs重组菌的酶活,结果显示表达BSH1重组菌的酶活最高,其次是BSH3和BSH2的重组菌,而以BSH4重组菌酶活最低。本研究结果表明,BSH1可能在L.plantarum ST-Ⅲ水解胆盐方面起着更为重要的作用,其次为BSH3,而BSH2和BSH4在L.plantarum ST-Ⅲ中对牛磺酸结合胆盐的水解能力较弱。

Abstract: Bile salt hydrolase( BSH),the enzyme deconjugating bile potentially plays an important role in reduction of blood cholesterol level,which has received a widespread attention. In this study,the recombinant Lactobacillus plantarum ST-Ⅲ were constructed by overexpressing four BSH genes and the BSH enzyme activities were determined.The result showed that L.plantarum ST-Ⅲ harboring BSH1 had a higher enzyme activity than the other three strains,then was the strains harboring BSH3 and BSH2,and the lowest activity was shown in ST-Ⅲoverexpressing BSH4,which indicated that the BSH1 might play a more important role in the hydrolysis of the conjuncted bile salts,then was BSH3,BSH2 and BSH4 successively.