重组大肠杆菌产耐高温Fe-SOD(H29A)的发酵条件优化

Optimization of Fermentation Process for a Hyperthermostable Fe-Superoxide Dismutase(H29A) Expressed in Recombinant E.coli BL21(DE3)

超氧化物歧化酶在药物和化妆品等工业中具有重要的应用价值。为了提高超氧化物歧化酶的产量,作者运用E.coli BL21(DE3)/p ET28a(+)-SOD重组表达系统,采用单因素实验和正交实验相结合的方法,研究了诱导表达条件和发酵培养基对重组大肠杆菌产超氧化物歧化酶的影响。实验结果表明,在培养基中添加1.20 g/L亮氨酸,30 g/L酵母粉且碳氮质量比为3,诱导剂浓度0.20 mmol/L,诱导温度37℃,诱导时间8 h的条件下,菌体生长量达到最高并且Fe-SOD(H29A)的产量达到全菌体蛋白的49.37%,表达量是LB培养基发酵的1.45倍。

Superoxide dismutase （SOD） is an important antioxidant enzyme which has been generally applied in pharmaceutical and cosmetics industries. A combination of single factor method and orthogonal design was utilized to study the effect of induction expression conditions and the fermentation medium on SOD production expressed in a recombinant E.coli BL21 （DE3）/pET28a（＋） -SOD and improve the production of SOD. The optimal expression level of 49.37% and 1.45 times of that in LB medium were achieved under the following condition including 1.20 g/L of leucine, 30 g/L of yeast extract, the carbon to nitrogen （C：N） ratio of 3：1,0.20 mmol/L IPTG, induce temperature at 37 ℃ and induction time over 8 h.