The direct recovery of recombinant hepatitis B core antigen from disruptate derived from continuous‐flow bead milling

Abstract

HBcAg (hepatitis B core antigen) is a nanoplex bioproduct that has a great potential in the development of therapeutic drugs and vaccines. In the present study, a continuous‐flow bead milling for the disruption of Escherichia coli was optimized and a direct recovery protocol to isolate the recombinant HBcAg from the unclarified E. coli disruptate was developed. The optimal condition for continuous‐flow bead milling for the release of HBcAg from E. coli was achieved at a feed flow rate of 15 litres/h, biomass concentration of 10% [ww/v (wet weight/vol.)] and impeller tip speed of 14 m/s. The sucrose‐density‐gradient analysis showed that the particulate form of the HBcAg released by this optimal condition is still preserved. In the direct purification of HBcAg from the unclarified disruptate, the AE‐EBAC (anion‐exchange expanded‐bed adsorption chromatography) technique was employed. A 54% adsorption and 50.7% recovery of HBcAg were achieved in this direct recovery process. The purity of HBcAg recovered was 49.8%, which corresponds to a purification factor of 2.0. ELISA showed that the HBcAg recovered is functionally active.