大肠杆菌植酸酶appA的融合表达及耐热性研究  

Fussion Expression and Study on Heat Resistance of the Phytase appA from Escherichia coli

作　　者：徐辉[1] 雷高鹏[1] 徐文华[1] 贺顺姬[1] 刘谊[1] 董明奇[1] 曹毅[1] 

机构地区：[1]四川大学生命科学学院四川省生物信息及代谢工程共享实验平台,成都610065

出　　处：《四川大学学报（自然科学版）》2006年第2期445-450,共6页Journal of Sichuan University(Natural Science Edition)

摘　　要：提取大肠杆菌(SUGL)基因组DNA,通过PCR方法从基因组扩增得到植酸酶基因ap-pA,测序结果表明该基因的ORF读框包含1440个核苷酸.将该基因重组于大肠杆菌表达载体pET-32a(+)中,导入大肠杆菌BL21(DE3),构建工程菌BL21(DE3)-pET32a-appA.对表达条件进行了优化,在30℃下,以0.1mmol/L IPTG诱导表达植酸酶,表达量达到10%以上.在37℃,用钒钼酸铵法测定了表达的植酸酶活性为40740.7U/g,同时观察不同加热温度对植酸酶活性的影响程度.发现融合表达的植酸酶的耐热性得到提高.Phytases catalyze the hydrolysis of phosphate moieties from phytic acid, thereby, resulting in the loss of ability of phytic acid to chelate metal ions. The supplementation of animal feed with phytase increases the bioavailability of phosphorus in monogastric animals besides reducing the phosphorus pollution in the areas of intensive livestock units. The phytase appA which is a promising candidate for industrial production of feed enzyme was introduced. Phytase gene appA was cloned from pMD-phy by polymerase chain reaction（PCR）. The gene appA was then cloned into the pmka^otic expression vector pET-32a. In the host BL21（DE3）, the phytase appA was expressed. The phytase activity was tested under different temperature and its thermostability was researched.

关 键 词：大肠杆菌 植酸酶 重组appA 耐热性 

分 类 号：Q81[生物学—生物工程]