嗜酸乳杆菌β-半乳糖苷酶基因的克隆及其作为食品级筛选标记的研究  

Cloning of β-Galactosidase Gene from Lactobacillus acidophilus and Study of Its Activity as a Food-Grade Selection Marker

作　　者：贺松[1] 龚芳红[1] 张德纯[1] 刘明方[1] 程芳[2] 郭亚楠[1] 

机构地区：[1]重庆医科大学分子医学与肿瘤研究中心,重庆400016 [2]西安交通大学医学院,陕西西安710061

出　　处：《食品与生物技术学报》2010年第5期777-781,共5页Journal of Food Science and Biotechnology

基　　金：重庆市教委资助项目(JK060306)

摘　　要：为研究嗜酸乳杆菌β-半乳糖苷酶基因(lacZ)作为食品级筛选标记的活性及筛选稳定性,作者从嗜酸乳杆菌基因组中克隆β-半乳糖苷酶基因并在乳酸乳球菌中表达,通过X-gal显色筛选阳性克隆;用X-gal显色筛选方法将重组乳酸乳球菌传60代,并测定β-半乳糖苷酶酶活和比活力。结果显示:通过表达有活性的β-半乳糖苷酶和X-gal显色可成功筛选出阳性克隆菌株;对借助X-gal传60代后的重组乳酸乳球菌进行β-半乳糖苷酶比活力检测,与X-gal筛选的第二代相比没有显著差异(P=0.592>0.05),与红霉素筛选比较也没有显著差异(P=0.882>0.05)。由此可见,β-半乳糖苷酶基因作为筛选标记具有较好的活性和稳定性,为以β-半乳糖苷酶基因作为筛选标记的食品级载体的研究奠定了基础。To study the selective activity and stability of β-galactosidase gene（lacZ） from Lactobacillus acidophilus as a food-grade selection marker,the lacZ gene from L.acidophilus was cloned and expressed in L.lactis.In this study,the selective activity was determined by X-gal-containing medium and the activity and specific activity of β-galactosidase by X-gal.The results showed that the positive recombinant strains were selected successfully by β-galactosidase activity and X-gal coloration.The β-galactosidase specific activity of the recombinant L.lactis after a period of 60 generations selected with X-gal was similar to that of the 2nd generation（P=0.5920.05）,and also similar to the 61st generation selected with Erythromycin（P=0.8820.05）.These results indicated that the β-galactosidase lacZ gene had good activity and stability as a selection marker,and it could be used as a selection marker for construction of a food-grade vector.

关 键 词：Β-半乳糖苷酶 嗜酸乳杆菌 乳酸乳球菌 食品级筛选标记 

分 类 号：Q78[生物学—分子生物学] Q939.11