Production of K1 (Streptokinase) Using Batch and Fed-Batch Culture of Recombinant E. coli

Abstract

This paper discusses the effects of medium composition, host strains, cultivation strategy, and plasmid stability on the growth and expression of KI (SK) recombinant fission protein expressed in E.coli under the control of 1pp-lac promoter. The production of recombinant KI (SK) fusion protein, was compared in batch and fed-batch culture. In batch culture a high dependence of the protein expression level on the host strain and culture medium was observed. The highest expression level of KI (SK) was obtained when the KS 474 (pINO 56) and TG 1 (pINO 56) strains were grown in synthetic medium, while in all cases a very low cell concentration was obtained In order to increase the final cell concentration, a high cell density cultivation (HCDC) process was carried out. The expression of KI (SK) using KS 474 (pINO 56) and TG 1 (pINO 56) strains was compared. A high difference related to the plasmid stability and cell growth was observed. By introducing fed-batch cultivation, the final cell dry weight and the specific expression level were increased significantly compared to batch cultivation. It was demonstrated that the expression form of KI (KS) recombinant protein (soluble or insoluble) depended on the culture conditions.