High-density fermentation and purification process for recombination high temperature-resistant hyperoxide dismutase

The present invention provides a high density fermentation and a purification process of a recombination high temperature resistance superoxide dismutase, the construction method of the invention includes: using gene coded for SOD in a thermophilic bacteria as a template, designing specific primer amplification target gene having restriction enzyme sites, after double digestion, connecting to plasmid vector pET28a after the same double digestion, constructing a recombinant plasmid, named for pSOD, transforming plasmid pSOD to competence escherichia coli BL21(DE3) by chemical transformation method, obtaining strain having high SOD yield after screening, completing the construction of SOD engineering bacteria; the fermentation process includes four steps of first order seed culture, secondary order feed culture, batch fermentation and induced expression, fermentation product SOD is finally obtained; the fermentation process realizes high level expression of SOD, the expression of the target protein is more than 60% of the bacterial protein total; SOD has excellent thermal stability and heat resistance, the expression product accounts for more than 60% of the whole proteins, and fully soluble protein, avoiding any trouble in the course of inclusion body renaturation; the purification process is simple, having high yield, lower cost, the final product SOD has high purification, high activity and strength stability.