Media Optimization for Production of Recombinant Carrier Protein (CRM197) in <i>Escherichia coli</i>

Abstract

Since the advent of vaccines, the mankind has benefited from the same and has been able to curb the mortality rate around the globe. Amongst different types of available vaccines, polysaccharide based vaccines are very widely used against various infectious diseases. The polysaccharide vaccines need to be conjugated with a carrier protein to make the vaccine more immunogenic. Recombinant Escherichia coli cells are the organism of choice for large scale production of a carrier protein because of its widely studied scientific aspects. In the present study, for proof of concept, the recombinant E. coli cells were cultured in Luria-Bertani media to check the expression of rCRM197. At 80L scale, it was observed that when recombinant E. coli cells were grown in a chemically defined media, it resulted in inconsistent growth and a long lag phase. When the defined media was supplemented with yeast extract, the lag phase of the culture was substantially reduced and the maximum growth of the culture was achieved. Protein expression was checked using SDS PAGE (Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis) and Western blot technique. The optimized media resulted in a robust fermentation process to achieve high cell density and maximum biomass for the production of recombinant protein.