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

Abstract:

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.