乳酸杆菌pPG质粒表达系统理想表达条件的探索  

Exploration of optimal expression conditions in Lactobacillus casei with pPG vector

作　　者：夏春丽[1] 马广鹏[1] 陈忠广[1] 秦玉敏[1] 徐义刚[1] 乔薪瑗[1] 姜雪[1] 李一经[1] 

机构地区：[1]东北农业大学动物医学院,哈尔滨150030

出　　处：《中国乳品工业》2007年第5期9-12,31,共5页China Dairy Industry

基　　金：高等学校科技创新工程重大项目培育基金项目(708019)

摘　　要：对乳酸杆菌pPG质粒表达系统理想表达条件进行了探索。以干酪乳杆菌Lactobacillus casei 393为宿主菌,β-葡萄糖苷酸酶(gusA)基因作为表达的报告基因,根据干酪乳杆菌的生长特性对细胞表面表达载体pPG表达过程中各个关键因素的影响进行了探索。得出最佳表达条件:将其培养于质量浓度为1%乳糖,初始pH值在6.0～6.5之间的MRS培养基中,30～32℃,静止培养至A590OD达0.5,培养时间约8 h,表达效率最高,外源蛋白的表达量可占菌体总蛋白的14%。The expression conditions of plasmid pPG have been explored, Escherichia coli β-Glucuronidase （gusA） gene was used as a reporter gene for analyzing expression conditions of pPG .mediating surface-anchored expression in Lactobacillus casei 393. According to the growth character of Lactobacillus casei, we have explored each critical fictor which influences the expression of pPG. The expression level of gusA could achieve 14.0% of the whole cell proteins When the recombinant L.casei393 was incubated in basal MRS medium ofpH between 6,0 and 6,5, supplemented with 1% lactose, at 30℃ or 32 ℃, without shaking, to the absorbance of A590OD reaching about 0.510, about 8h. Exploring each critical fictor of affecting gusA＇s expression provides the basis for expressing Other active protein （peptide）.

关 键 词：乳酸杆菌 干酪乳杆菌 β-葡萄糖苷酸酶gusA 表达系统 

分 类 号：Q933[生物学—微生物学]