A high cell density fermentation strategy to produce recombinant malarial antigen in E. coli.

A high cell density cultivation method was developed to produce recombinant PvRII, a malaria vaccine candidate, in E. coli for use in vaccine studies. Cells were grown in completely defined media and glucose was fed to achieve a specific growth rate of 0.12 h(-1) until cells reached 55 g dry wt l(-1). Culture was then induced with 1 mM: IPTG and cells were further grown for 4 h to reach 85 g dry wt l(-1) at 0.1 h(-1). Recombinant PvRII was purified from inclusion bodies under denaturing conditions using metal affinity chromatography which yielded 10 mg PvRII g(-1) dry wt. After refolding, PvRII was greater than 98% pure, homogeneous and functionally active in that it specifically bound Duffy positive human red cells.