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.