Abstract: In this study, the recombinant Lactobacillus casei LC2W were constructed for overexpressing four bsh genes from L. plantarum ST-III and the Bile salt hydrolase (BSH) enzyme activities were determined. It was shown that the four recombinant strains all showed a lower enzyme activity than the host, indicating that the bsh gene overexpression could not achieve the goal of enhancing the hydrolysis of the bile salts.

Key words: bile salt hydrolase; Lactobacillus casei LC2W; gene cloning and overexpression; enzyme activity

摘要： 从胆盐水解酶的特性出发,在干酪乳杆菌LC2W中过量表达Lactobacillus plantarum ST-Ⅲ 4种胆盐水解酶同工酶,通过酶活性的测定研究胆盐水解酶对干酪乳杆菌水解胆盐的作用.结果表明:实现了4种胆盐水解酶在干酪乳杆菌LC2W的过表达;利用茚三酮显色法测定的4种重组菌胆盐水解酶活性较宿主LC2W都不同程度地降低;在干酪乳杆菌LC2W中过量表达L.plantarum ST-Ⅲ的胆盐水解酶基因达不到提高该菌水解胆盐能力的目的.

关键词: 胆盐水解酶；干酪乳杆菌LC2W；克隆表达；酶活性