初始碳源对苏云金芽孢杆菌cry—lacZ融合基因表达的影响

Effects of Primzry Carbon Sources on the Expression of Cry-lac Z in Bacillus thuringiensis

分别采用携带cry1A上游区、突变或缺失上游区的重组穿棱载体pHT/pSGMU-P,电转化到苏云金芽孢杆菌不同菌株中,并经含不同初始碳源的Gtris培养基培养,检测BtI-lacZ融合基因的表达.结果表明,各种转化子的β-半乳糖苷酶活性随着培养基中初始碳源的不同而异,在以丙酮酸钠为初始碳源的培养基中,BtI-lacZ的表达量最高,以葡萄糖为初始碳源的次之,在琥珀酸钠中最低,说明cry基因的表达与初始碳源的种类和细胞的代谢有关.

A recombined shuttle vectors pHT/pSGMU with wild mutational or deleted upstream of cry 1A promoter were transferred into various strains of Bacillus thuringiensis . The strains then were cultured on Gtris medium containing different primary carbon sources to test the expression of Btl lacZ fusion. The results showed that β galactosidase activity of various transformants varied in various primary carbon sources. Among them the expression of Btl lacZ was the highest on medium contained pyruvate, the second was that with glucose, and the lowest was that contained succinate. These suggested that the expression of cry gene was related to the primary carbon sources and the metabolism of cells on Bacillus thuringiensis .