摘要
实现了戊二酰基-7-氨基头孢烷酸(GL-7ACA)酰化酶的组成型表达,并通过替换重组质粒启动子的RBS序列,在摇瓶培养条件下,使新构建的重组质粒pGEMKT-HPRfACY在大肠杆菌JM105中表达GL-7ACA酰化酶酶活达到0.44U/mL,是替换前的2倍.使用廉价的玉米浆作为培养基中氮源主要来源,使JM105/pGEMKT-HPRfACY菌株酶活提高到2.98U/mL.采用补料批式培养,利用流加营养物控制发酵中后期的pH值,在pH为7.5的条件下,酶活峰值达到6.37U/mL.该体系无需诱导,工艺操作过程简单,成本低廉.
The constitutive expression of glutaryl-7-amidocephalosporanic acid （GL-7-ACA） acylase was realized. Based on it, a new plasmid pGEMKT-HPfACY with optimized RBS was constructed and transformed into E. coli JM 105. After culturing in LB media, this recombinant strain reached an activity of 0.44 U/mL. This activity was twice of former one while the activity of the strain JM 105/pGEMKT-HPRfACY reached as high as 2.98 U/mL using corn-steep as culture media. The acylase activity of recombinant strain hit 6.37 U/mL, using a strategy of controlling pH 7.5 byadding nutrient such as glycerin.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2008年第1期140-143,共4页
The Chinese Journal of Process Engineering
